The MELANIE project: from a biopsy to automatic protein map interpretation by computer.

The goals of the MELANIE project are to determine if disease-associated patterns can be detected in high resolution two-dimensional polyacrylamide gel electrophoresis (HR 2D-PAGE) images and if a diagnosis can be established automatically by computer. The ELSIE/MELANIE system is a set of computer programs which automatically detect, quantify, and compare protein spots shown on HR 2D-PAGE images. Classification programs help the physician to find disease-associated patterns from a given set of two-dimensional gel electrophoresis images and to form diagnostic rules. Prototype expert systems that use these rules to establish a diagnosis from new HR 2D-PAGE images have been developed. They successfully diagnosed cirrhosis of the liver and were able to distinguish a variety of cancer types from biopsies known to be cancerous.     

Trivalent lanthanide interactions with a terdentate bis(dialkyltriazinyl)pyridine ligand studied by electrospray ionization mass spectrometry

The 2,6-bis(5,6-dialkyl-1,2,4-triazin-3-yl)pyridines (DATPs) belong to a new family of extracting agents recently developed in the framework of nuclear fuel reprocessing. These molecules exhibit exceptional properties to separate actinides(III) from lanthanides(III) in nitric acid solutions. A previous work showed that electrospray ionization mass spectrometry (ESI-MS) is a reliable technique to provide solution data such as stoichiometries and conditional stability constants of various DATP complexes with europium and evidenced the unusual capability of DiPTP [bis(di-iso-propyltriazinyl)pyridine] ligand to form 1:3 complexes in nitric acid solution. This latter result is further investigated by considering DiPTP complexation features with the complete lanthanide family. As a starting point of the experimental procedure used for stability constant evaluation, the intensity distribution of ions detected by ESI-MS is studied for solutions containing Ln(NO(3))(3) in water/methanol (1:1 v/v) with the pH value set at 2.8 and 4.6 by HNO(3) additions. At pH 2.8, the nitrate anions are found to prevent lanthanides from processes occurring within the ion source: redox phenomena or gas-phase reactions with methanol which give species such as [Ln(MeO)(2)](+). Thus, the total intensity of MS signals from [Ln(NO(3))(2)(H(2)O)(p)(MeOH)(n)](+) ions is found proportional to the metal ion concentration. At pH 4.6, with lower nitrate concentration, the nature of the species identified on mass spectra depends on the electronic properties of the lanthanide elements. It is shown that Ln(III) complexation with DiPTP leads to the exclusive formation of 1:3 complexes with the whole lanthanide series which may be due not only to the hydrophobic exterior of the ligand but also to the unusual electronic density distribution in DATP ligands as compared with other aza-aromatic ligands. The conditional stability constants of the 1:3 lanthanide(III) complexes with DiPTP have been determined at pH 2.8 and are found to increase almost regularly from La (log beta(3)(app) = 11.7 +/- 0.1) to Lu (log beta(3)(app) = 16.7 +/- 0.8). Moreover, the kinetic stability of the gas-phase 1:3 complexes obtained by electrospray has been investigated by energy-resolved collision-induced dissociation and provides useful information on the bonding and structure.     

Conformational transition of poly(methacrylic acid) in methanol–water mixtures

The effect of ionization on the potentiometric and viscometric behavior of both poly(methacrylic acid) (PMA) and poly(acrylic acid) (PAA) was investigated in methanol–water mixtures. The potentiometric and viscosity data revealed that the conformational change which takes place for PMA in water gradually disappears with increasing content of methanol in methanol–water mixtures. For mixtures containing 40 and 50% methanol, the behavior of PMA solutions becomes similar to that of PAA, i.e., the discontinuity versus the degree of ionization is no longer detectable and the molecule unfolds regularly upon ionization. The addition of methanol leads to the breakdown of the compact structure of PMA which is stabilized, at low degree of ionization in water, by nonelectrostatic interactions between the methyl groups of PMA.     

Preparation and Absolute Configuration of (−)-(E)-α-trans-Bergamotenone

The synthesis, absolute configuration, and olfactive evaluation of (?)-(E)-α-trans-bergamotenone (= (?)-(1′S,6′R,E)-5-(2′,6′-dimethylbicyclo[3.1.1]hept-2′-en-6′-yl)pent-3-en-2-one; (?)- 1 ), as well as its homologue (?)- 19 are reperted. The previously arbitrarily attributed absolute configuration of 1 and of (?)-α-trans-bergamotene (= (?)-(1 S,6R)-2,6-dimethyl-6-(4-methylpent-3-enyl)bicyclo[3.1. 1]hept-2-ene; (?)- 2 ), together with those of the structurally related aldehydes (?)- 3a,b and alcohols (?)- 4a,b , have been rigorously assigned.     

Large-Scale Purification of Water-Soluble Polysaccharides from Flaxseed Mucilage, and Isolation of a New Anionic Polymer

Summary Viscous flaxseed mucilage has previously been described as a mixture of two polysaccharides (acidic and neutral). In this study, we have shown that a combination of ion exchange and size exclusion chromatography enables purification of three distinct polysaccharides. Molecular weight (Mw) analysis, performed by size-exclusion chromatography on line with a multi-angle laser light-scattering detector, revealed that the main polysaccharide (75%) was a neutral polymer with a Mw of approximately 1.2 × 10⁶ g mol^–1. The two others were acidic polysaccharides denoted AF₁ (3.75%, 6.5 × 10⁵ g mol^–1) and AF₂ (21.25%, 1.7 × 10⁴ g mol^–1).Presented at: International Symposium on Separation and Characterization of Natural and Synthetic Macromolecules, Amsterdam, The Netherlands, February 5–7, 2003     

Recombinant human estrogen, androgen and progesterone receptors for detection of potential endocrine disruptors

This work reports the binding capacity of various chemicals (so-called endocrine disruptors) to recombinant human steroid receptors (hER, hPR and hAR). The tested chemicals are organochlorine insecticides (DDT and its metabolites, methoxychlor, aldrin, dieldrin, chlordecone, lindane, trichlorobenzene), estrogenic insecticides (endosulfan, toxaphene, nonachlor), herbicides (alachlor and atrazine), fungicides (benomyl and vinclozolin), industrial chemicals (nonylphenol, bisphenol A, diphenylphtalate), antioxidants (butylated hydroxyanisol) and some phytoestrogens. Except for phytoestrogens, most of the tested chemicals (DDT and its metabolites, aldrin, - and -endosulfan, toxaphen, trans-nonachlor) show higher affinities for hPR than for hER, indicating that the interaction with the progesterone receptor could contribute to the endocrine-disrupting effects imputed to these chemicals. We propose to use binding assays using recombinant human steroid receptors as screening tools for the detection of endocrine disruptors in various samples.     

A method for the determination of some organophosphorus insecticides in human serum

Summary A simple and rapid method for the determination of organophosphorus insecticides in serum of poisoned patients is described. The compounds are extracted with benzene and the extraction residue is gas chromatographed on a glass capillary column with alkali flame ionisation detection. Concentrations from 2 ng cm⁻³ can be determined. As an example, results of the analysis of serum samples of three patients, poisoned with parathion and methylparation, are given.     

The highest water exchange rate ever measured for a Gd(III) chelate

The complex [Gd(L)(H2O)]3- (H(6)L =N,N'-bis(6-carboxy-2-pyridylmethyl)ethylenediamine-N,N'-methylenephosphonic acid) displays the highest water exchange rate ever measured for a Gd(III) chelate (k(298)(ex)= 8.8 x 10(8) s(-1)), which is attributed to the flexibility of the metal coordination environment.