Christophe Boissard

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Forty native Mediterranean plant species were screened for emissions of the C5 and C10 hydrocarbons, isoprene and monoterpenes, in five different habitats. A total of 32 compounds were observed in the emissions from these plants. The number of compounds emitted by different plant species varied from 19 (Quercus ilex) to a single compound emission, usually(More)
Vasoactive intestinal peptide (VIP) receptors are widely distributed in different tissues or carcinoma cells originating from entoderm and have been shown to regulate the growth of colonic adenocarcinoma cells through the action of cyclic AMP (cAMP). After exposure of cultured HT-29 human colonic carcinoma cells to 10(-8) M VIP, the cAMP-mediated signals in(More)
Increases in the production of terpene- and phenolic-like compounds in plant species under abiotic stress conditions have been interpreted in physiological studies as a supplementary defense system due to their capacity to limit cell oxidation. From an ecological perspective however, these increases are only expected to confer competitive advantages if they(More)
In our developed reverse phase high performance liquid chromatography, four forms of M125I-VIP have been isolated free from unlabeled VIP and other iodinated components. The quicker eluting M125I-VIP forms (oxidised and reduced) have a consistently and significantly low non-specific binding with specific target cells of VIP (HT-29) as compared to the late(More)
Vasoactive intestinal peptide (VIP), composed of 28 amino acids, is a multifunctional neurotransmitter. We have demonstrated here that its action on human transformed colonic epithelial (HT-29) cells is mediated through the induction of interferon (IFN) synthesis. We have found that these cells have a functional receptor for IFN alpha 2; binding was(More)
Using a statistical approach based on artificial neural networks, an emission algorithm (ISO LF) accounting for high (instantaneous) to low (seasonal) frequency variations was developed for isoprene. ISO LF was optimised using an isoprene emission data base (ISO-DB) specifically designed for this work. ISO-DB consists of 1321 emission 5 rates collected in(More)
Using a statistical approach based on artificial neural networks, an emission algorithm (ISO-LF) accounting for high to low frequency variations was developed for isoprene emission rates. ISO-LF was optimised using a data base (ISO-DB) specifically designed for this work, which consists of 1321 emission rates collected in the literature and 34 environmental(More)
Endocytosis of vasoactive intestinal peptide (VIP) and of transferrin (Tf) was comparatively studied in human cancerous colonic HT-29 cells. Cellular depletion in potassium inhibits the internalization of VIP (23%) and to a greater extent (42%) that of Tf. This indicates that clathrin-coated pits are also involved, at least in part, in VIP uptake. The(More)