The structure of the monomeric porcine odorant binding protein sheds light on the domain swapping mechanism

The X-ray structure of the porcine odorant binding protein (OBPp) was determined at 2.25 A resolution. This lipocalin is a monomer and is devoid of naturally occurring bound ligand, contrary to what was observed in the case of bovine OBP [Tegoni, M., et al. (1996) Nat. Struct. Biol. 3, 863-867; Bianchet, M. A., et al. (1996) Nat. Struct. Biol. 3, 934-939]. In this latter protein, a dimer without any disulfide bridges, domain swapping was found to occur between the beta- and alpha-domains. A single Gly (121) insertion was found in OBPp when it was compared to OBPb, which may prevent domain swapping from taking place. The presence of a disulfide bridge between the OBPp beta- and alpha-domains (cysteines 63 and 155) may lock the resulting fold in a nonswapped monomeric conformation. Comparisons with other OBPs indicate that the two cysteines involved in the OBPp disulfide bridge are conserved in the sequence, suggesting that OBPp may be considered a prototypic OBP fold, and not OBPb.     

Speciation of organometallic compounds in environmental samples by gas chromatography after flow preconcentration on fullerenes and nanotubes

The development of a simple speciation method for the determination of lead (trimethyllead(I), dimethyllead(II), triethyllead(I), and diethyllead(II)), mercury (methylmercury(I), ethylmercury(I), mercury(II)), and tin (n-butyltin(III), di-n-butyltin(II), tri-n-butyltin(I), tin(IV)) compounds in environmental samples was described. The potential of C70 fullerenes and multiwalled carbon nanotubes (MWNTs) as sorbents was investigated for the first time; this study revealed that there are no significant differences between them in terms of sensitivity, selectivity, precision, and reusability. Comparative studies showed that MWNTs and C60 and C70 fullerenes were superior to graphitized carbon black and RP-C18 for the extraction of the 11 compounds studied. The accuracy of the MWNT method was evaluated from recovery values with two standard reference coastal sediments, and good concordance in the results were obtained. Detection limits of 0.5-2 pg/mL were obtained when using a sorbent column containing 160 mg of MWNTs (sample breakthrough, 50 mL of water). The method was successfully applied to the determination of lead, mercury, and tin compounds in water and coastal sediment samples with satisfactory results.     

4-Hydroxynonenal and cholesterol oxidation products in atherosclerosis

4-Hydroxynonenal (HNE) is by far the most investigated aldehydic end-product of oxidative breakdown of membrane n-6 polyunsaturated fatty acids. Its potential involvement in the pathogenesis of atherosclerosis has been corroborated by its consistent detection in both oxidized LDL and fibrotic plaque in humans. HNE has been shown to activate both macrophage and smooth muscle cells, i.e. the two key cell types in chronic inflammatory processes characterized by excessive fibrogenesis. By signalling to the nucleus, the aldehyde may up-regulate in these cells both expression and synthesis of monocyte chemotactic protein 1 (MCP-1) and transforming growth factor beta1 (TGFbeta1). Oxysterols, namely 27 carbon atoms oxidation products of cholesterol, are found in relatively high amount in LDL from hypercholesterolemic individuals and are consistently detectable in foam cells and necrotic core of human atherosclerotic lesion. As for HNE, the challenge of cells of the macrophage lineage with a mixture of oxysterols like that detectable in hypercholesterolemic individuals led to a marked overexpression of TGFbeta1 and MCP-1. Both HNE and oxysterols then appear to be candidates for a primary role in the progression of the atherosclerotic process.     

Effect of natural fermentation on the content of inositol phosphates in lentils

The effects of natural fermentation upon phytic acid and less phosphorylated inositol phosphates ofLens culinaris var vulgaris cultivar Magda-20 were investigated. Seven fermentation runs were made following a 2² complete factorial design with three replicated centre points to study the effect of different conditions of temperature (28, 35 and 42°C) and broth concentration (79, 150 and 221 g/l). Samples were taken for each of them at daily intervals (0, 24, 48, 72 and 96 h). The pH value declined sharply in the first 24 h of fermentation, becoming stabilized from this time. The relation between lactic acid and titratable acidity presented important differences between the different fermentations, ranging from 30–80%. Phytic acid (IP ₆), inositol pentakis (IP ₅), tetrakis (IP ₄) and tris-(IP ₃) phosphates were quantitatively determined. The content of total inositol phosphates showed a maximum reduction of 63% at 72 h under the fermentation conditions of 42°C and 79 g/l.     

Combined effect of enterocin AS-48 and high hydrostatic pressure to control food-borne pathogens inoculated in low acid fermented sausages

The single and combined effects of enterocin AS-48 and high hydrostatic pressure (HHP) on Listeria monocytogenes, Salmonellaenterica, and Staphylococcus aureus was investigated in fuet (a low acid fermented sausage) during ripening and storage at 7 °C or at room temperature. AS-48 (148 AU g⁻¹) caused a drastic 5.5 log cfu g⁻¹ decrease in L. monocytogenes (P < 0.001) and a significant (P < 0.01) inhibition (1.79 logs) for Salmonella at the end of ripening (10 d). After pressurization (400 MPa) and storage Listeria counts remained below 5 cfu g⁻¹ in all fuets containing AS-48 (pressurized or not). HHP alone had no anti-Listeria effect. HHP treatment significantly reduced Salmonella counts, with lowest levels in pressurized fuets with AS-48. S. aureus showed similar growth for all treatments and storage conditions. These results indicate that AS-48 can be applied alone to control L. monocytogenes and combined with HHP treatment to control Salmonella in fuets.     

Modelling of ionospheric high-order errors for new generation GNSS

In dual frequency Global Positioning System receivers, the ionospheric propagation delays are commonly estimated and corrected using the “ionosphere free” combinations of pseudo-range observables. With this method, the ionospheric delay is estimated at the first-order proportional to the inverse of the frequency square. However, higher-order terms exist that may be taken into account when precise corrections are required. The second-order term results from the influence of the geomagnetic field on the ionospheric propagation of the signals. The third-order term includes the refractive effects due to the bending of the ray. Contributions of the second- and third-order terms typically amount to values in the centimetre and millimetre ranges, respectively. In a near future, triple-frequency Global Navigation Satellite Systems transmitting high-resolution codes will become available. These systems are expected to provide a noticeable improvement in accuracy. This paper focuses on the Galileo signals as Galileo In-Orbit Validation Element (GIOVE) signals are now available for acquisition. A solution relying on the triple-frequency characteristics of a signal-in-space is investigated with results based on first measurements of GIOVE-A signals. Eventually, a method is described that relies on precise dual-frequency phase measurements to evaluate the second-order ionospheric contribution for Galileo data.     

The association between stunting and overweight in Latin American and Caribbean preschool children

BACKGROUND: Although some segments of the population continue to suffer from undernutrition, other groups exhibit excess weight gain, resulting in the coexistence of undernutrition and obesity and leading to a dual nutritional burden. OBJECTIVE: To explore the association between stunting and overweight in preschool children from Latin American and Caribbean countries. METHODS: We analyzed cross-sectional data from children 0 to 5 years of age from 79 nationally representative surveys, compiled by the World Health Organization (WHO) Global Database on Child Growth and Malnutrition. This database defines stunting as low height-for-age and overweight as high weight-for-height. These variables were explored with the use of simple and multiple regression models. RESULTS: There were significant differences between subregions in the prevalence of stunting: the prevalence was 7.4% in the Caribbean, 11.3% in South America, and 20.4% in Central America (p < .001). In contrast, the estimated prevalence of overweight was similar between subregions. The overall prevalence rates of stunting and overweight in Latin America and the Caribbean in the year 2000 were 13.7% and 4.3%, respectively. We found an inverse relationship (r = -0.3) between the prevalence rates of overweight and stunting, overall and within subregions. South America exhibited the highest slope and intercept on the regression of overweight on stunting. CONCLUSIONS: Different subregions of Latin America and the Caribbean have different prevalence rates of childhood stunting but similar prevalence rates of overweight. There is an inverse relationship between stunting and overweight. The South American subregion had the highest increase and prevalence of overweight of the Latin American region.     

Genetic bases of the nutritional approach to migraine

ABSTRACT

Migraine is a common multifactorial and polygenic neurological disabling disorder characterized by a genetic background and associated to environmental, hormonal and food stimulations. A large series of evidence suggest a strong correlation between nutrition and migraine and indicates several commonly foods, food additives and beverages that may be involved in the mechanisms triggering the headache attack in migraine-susceptible persons. There are foods and drinks, or ingredients of the same, that can trigger the migraine crisis as well as some foods play a protective function depending on the specific genetic sensitivity of the subject. The recent biotechnological advances have enhanced the identification of some genetic factors involved in onset diseases and the identification of sequence variants of genes responsible for the individual sensitivity to migraine trigger-foods. Therefore many studies are aimed at the analysis of polymorphisms of genes coding for the enzymes involved in the metabolism of food factors in order to clarify the different ways in which people respond to foods based on their genetic constitution.

This review discusses the latest knowledge and scientific evidence of the role of gene variants and nutrients, food additives and nutraceuticals interactions in migraine.