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Abstract: In this work we present a biosensor based on olfactory receptors as a new bioelectronic device for detecting the presence and for measuring the concentration of specific odorants. To increase the surface of transducers, and consequently amplify the electrochemical signal, we generated gold nanoparticles on the surface of gold electrode. The characterization of the nanoparticles modified electrode surface allow to determine an increase of the surface area by a factor of 2.6 ±.0.4 (n = 4). Nanosomes from yeast containing olfactory receptor OR1740 with a cmyc tag were put in contact with the anti-cmyc antibody modified electrodes. Immobilization of nanosomes led to an increase in charge transfer resistance. This effect is amplified in the presence of gold nanoparticles by a factor of 3 ± 0.5. [Copyright &y& Elsevier]

Objective: The study mapped French people's views regarding the acceptability of posthumous reproduction., Background: Posthumous reproduction - the use of a deceased person's gametes for procreative purposes -is a controversial procedure because it involves a series of ethical issues, namely the surviving partner's rights to procreation, the emotional feelings and financial interests of other family members, and the government's interest in maintaining orderly inheritance rules., Methods: A convenience sample of participants aged 19-68 (104 lay people, 47 health professionals and 15 lawyers) were presented with 48 realistic stories that were composed according to a four-factor within-subject design: marital status (married for about 10 years with children, married for about three years without children, and cohabiting for three years without children) × attitude of the deceased's parents (favourable vs. unfavourable to posthumous procreation) × time elapsed since the partner's death (three months vs. nine months) × deceased's wishes (written consent, oral consent given in front of credible witnesses, unknown wishes, and unfavourable attitude)., Results: Through cluster analysis, four qualitatively different positions were found. They were called Never Acceptable (35% of the sample, mostly health professionals, lawyers and regular attendees to the church or temple), Tolerable in a Few Cases (28%), Depends on Deceased's Wishes (22%, mostly lay people) and Quite Acceptable (16%, mostly lay people)., Conclusions: About half of French lay people view the current legislation regarding posthumous assisted reproduction in a country such as the UK as more appropriate than the French legislation.

Native porcine odorant-binding protein (OBP) bears eleven sites of phosphorylation, which are not always occupied in the molecular population, suggesting that different isoforms could co-exist in animal tissues. As phosphorylation is a dynamic process resulting in temporary conformational changes that regulate the function of target proteins, we investigated the possibility that OBP isoforms could display different binding affinities to biologically relevant ligands. The availability of recombinant proteins is of particular interest for the study of protein/ligand structure-function relationships, but prokaryotic expression systems do not perform eukaryotic post-translational modifications. To investigate the role of phosphorylation in the binding capacities of OBP isoforms, we produced recombinant porcine OBP in two eukaryotic systems, the yeast, Pichia pastoris, and the mammalian CHO cell line. Isoforms were separated by anion exchange HPLC, and their phosphorylation sites were mapped by MALDI-TOF mass spectrometry and compared to those of the native protein. Binding experiments with ligands of biological relevance in the pig, Sus scrofa, were performed by fluorescence spectroscopy on two isoforms of recombinant OBP expressed in the yeast. The two isoforms, differing only by their phosphorylation pattern, displayed different binding properties, suggesting that binding specificity is driven by phosphorylation.

We report here the results of human olfactory receptor (OR) 17-40 stimulation with some odorants probed by means of the double-channel surface plasmon resonance platform NanoSPR-6. OR 17-40 tagged with N-terminal cmyc sequence was heterologously co-expressed with Galpha(olf) protein in yeast, and receptor-carrying nanosomes were prepared from yeast membrane fraction. Then, receptors were specifically captured via anti-cmyc antibody attached to the gold-coated substrate in orientated or random way. Measurement of odorants effects were carried out in the presence of GTP-gamma-S in differential mode in order to compensate bulk changes of refractive index. For the first time, biosensing efficiency of olfactory films was discussed in terms of their thickness and Galpha(olf) accessibility to GTP-gamma-S. Bell-shaped response profile with two maxima (near 1 nM and near 1 microM) was established for helional, which is documented as highly specific agonist of OR 17-40. Unrelated odorant heptanal used as control, did not evoke significant variations of differential signal.

Head rot of broccoli caused by Pseudomonas marginalis (Brown) Stevens and P. fluorescens Migula is a major disease in Brittany (France). To date, no accession with a satisfactory field resistance has been identified, and available pesticides are not effective in controlling the disease. The aim of this study was to test whether acibenzolar-S-methyl (ASM), DL-3-aminobutyric acid (BABA) and potassium phosphonate (K(2)HPO(3)), known to induce resistance against various diseases, can help protect broccoli against head rot. The susceptible broccoli F1 hybrids Marathon and Shogun were grown in a greenhouse until head formation. They were then sprayed with ASM (0.23 mM AI), BABA (20 mM AI) or potassium phosphonate (37.41 mM AI) until runoff. In one experiment, heads from treated plants were excised, inoculated (10(4) cfu ml(-1)) and incubated in Magenta GA7 vessels. In another experiment, heads were inoculated on treated living plants. Disease ratings were made 5 days after inoculation. Antibiotic- and water-treated plants served as controls. Results obtained showed that, on excised treated heads, potassium phosphonate was not protective and disease scores were comparable with those of the water control. BABA- and ASM-treated excised heads were poorly, but significantly, protected. On whole plants with heads attached, the latter two compounds were much more effective. ASM-induced resistance increased in effectiveness over 8 days after inoculation, whilst that induced by BABA decreased. This result suggests that testing disease resistance inducers on excised broccoli heads is not accurate. ASM and BABA may offer alternative methods for controlling head rot of broccoli., (Copyright 2005 Society of Chemical Industry.)

Receptors for the luteotropin/human chorionogonadotropin hormone belong to the G-protein-coupled receptor family by their membrane-anchoring domains. They also possess a large extracellular domain (ECD) responsible for most of the hormone-receptor interactions. Structure-function studies identified several contacts between hormone and receptor ECD, but the precise topology of the complex is still unknown because of the lack of suitable heterologous expression means. Receptor ECDs exhibit leucine repeats and have been modelized on the basis of the three-dimensional structure of the porcine ribonuclease inhibitor, the first structurally known leucine-rich repeats protein. Here we report overexpression (up to 20 mg per liter) and purification to homogeneity of a soluble human chorionogonadotropin-ECD receptor complex secreted by stably cotransfected Chinese hamster ovary cells. Biochemical analysis and surface plasmon resonance data were in favor of a unique dimer with a 1:1 ligand-receptor stoichiometry. Immunopurified complex was submitted to circular dichroism characterization; CD spectra deconvolution indicated more than 25% alpha helices contributed by the receptor, in agreement with the porcine ribonuclease inhibitor-based modelization.

The porcine follitropin receptor-encoding cDNA (pFSHR) was cloned using reverse transcription-polymerase chain reaction (RT-PCR). Total RNA from porcine granulosa cells was used as template. Two overlapping cDNA fragments encoding, respectively, aa 1 to 290 and aa 191 to 694 of the pFSHR were obtained. Taken together, the two fragments represented the whole coding sequence, assuming a comparable length for the FSHR from the porcine, rat and human species. Functionality of the cloned receptor was assessed by expression experiments; COS cells transfected with the pFSHR cDNA exhibited high-affinity specific binding for [125I]hFSH and FSH-dependent cAMP production. The primary sequence of the porcine FSHR N-terminal hormone-binding domain showed high percentages of identity with the sequences from ovine, human, and rat origins. A truncated form of the pFSHR cDNA, lacking aa 75 to 124 in the N-terminal domain, was also cloned and sequenced. A PCR-derived cDNA fragment of 1.45 kb was used as gene-specific hybridisation probe to map the pFSHR-encoding gene by radioactive in situ hybridization. This gene was found co-localized (as in human) with the porcine lutropin hormone receptor (pLHR)-encoding gene on the q2.2-q2.3 region of pig chromosome 3.