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See detailMALDI-FTICR MS Imaging as a Powerful Tool to Identify Paenibacillus Antibiotics Involved in the Inhibition of Plant Pathogens
Debois, Delphine ULg; Ongena, Marc ULg; Cawoy, Hélène ULg et al

in Journal of the American Society for Mass Spectrometry (2013), 24(8), 1202-1213

Nowadays, microorganisms are more and more often used as biocontrol agents for crop protection against diseases. Among them, bacteria of Bacillus and Paenibacillus genders are already used as commercial ... [more ▼]

Nowadays, microorganisms are more and more often used as biocontrol agents for crop protection against diseases. Among them, bacteria of Bacillus and Paenibacillus genders are already used as commercial biocontrol agents. Their mode of action is supposed to be related to their production of antibiotics, such as cyclic lipopeptides, which exhibit great antimicrobial activities. We chose to work with a Paenibacillus polymyxa strain (Pp56) very resistant to various microorganisms. The bacteria were grown simultaneously with Fusarium oxysporum and we applied matrix-assisted laser desorption/ionization-Fourier transform ion cyclotron resonance (MALDI-FTICR) mass spectrometry to identify the antibiotics compounds present in the fungus growth inhibition area. We, therefore, identified fusaricidins A, B, and C and numerous members of the LI-F antibiotics family. MALDIFTICR mass spectrometry imaging was then used to follow the diffusion of lipopeptides involved in the inhibitory activity over time. We analyzed the molecular content of the inhibitory area at different Pp56 and Fusarium incubation durations and concluded that some lipopeptides such as fusaricidin B and a mixture of LI-F05b/06b/08a were mainly involved in the defense mechanism of Pp56. Our study confirms that MALDI imaging may be a powerful tool to quickly determine which molecular species is involved in an antagonism with another microorganism, avoiding time-consuming steps of extraction, purification, and activity tests, which are still commonly used in microbiology. [less ▲]

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See detailMALDI-In Source Decay Applied to Mass Spectrometry Imaging: A New Tool for Protein Identification.
Debois, Delphine ULg; Bertrand, Virginie ULg; Quinton, Loïc ULg et al

in Analytical Chemistry (2010), 82(10), 3969-4304

Matrix-assisted laser desorption ionization-mass spectrometry (MALDI-MS) imaging is a powerful technique giving access to the distribution of a large range of biomolecules directly from a tissue section ... [more ▼]

Matrix-assisted laser desorption ionization-mass spectrometry (MALDI-MS) imaging is a powerful technique giving access to the distribution of a large range of biomolecules directly from a tissue section, allowing, for example, the discovery of new pathological biomarkers. Nevertheless, one main difficulty lies in the identification of the detected species, especially proteins. MALDI-in source decay (ISD) is used to fragment ions directly in the mass spectrometer ion source. This technique does not require any special sample treatment but only the use of a specific MALDI matrix such as 2,5-dihydroxybenzoic acid or 1,5-diaminonaphthalene. MALDI-ISD is generally employed on classical, purified samples, but here we demonstrate that ISD can also be performed directly on mixtures and on a tissue slice leading to fragment ions, allowing the identification of major proteins without any further treatment. On a porcine eye lens slice, de novo sequencing was even performed. Crystallins not yet referenced in databases were identified by sequence homology with other mammalian species. On a mouse brain slice, we demonstrate that results obtained with ISD are comparable and even better than those obtained with a classical in situ digestion. [less ▲]

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See detailMALDI-TOF MS en Microbiologie clinique
MEEX, Cécile ULg

Learning material (2016)

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See detailMALDI-TOF/TOF sequencing of peptide toxins from animal venoms
Quinton, Loïc ULg; Echterbille, Julien ULg; Gilles, Nicolas et al

Poster (2010, April 16)

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See detailMALDI-Top-Down of Proteins: Overview and Applications
Quinton, Loïc ULg; Demeure, Kevin ULg; Resemann, Anja et al

Conference (2009, June)

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See detailMale aromatase knockout mice acquire a conditioned place preference for cocaine but not for contact with an estrous female
Pierman, S.; Tirelli, Ezio ULg; Douhard, Quentin ULg et al

in Behavioural Brain Research (2006), 174(1), 64-69

We have previously shown that male mice carrying a targeted mutation in the Cyp19 gene which encodes the aromatase enzyme (aromatase knockout or ArKO), showed a reduced interest to investigate volatile ... [more ▼]

We have previously shown that male mice carrying a targeted mutation in the Cyp19 gene which encodes the aromatase enzyme (aromatase knockout or ArKO), showed a reduced interest to investigate volatile odors from conspecifics in a Y-maze. We asked here whether the incentive value of reproductively relevant odors is reduced in ArKO males by comparing the ability of male wild-type (WT) and ArKO mice to learn a conditioned place preference using exposure to reproductively relevant odors as incentive stimuli. When the presence of an anesthetized estrous female or soiled bedding from estrous females was used as incentive stimuli, only WT and not male ArKO mice showed conditioned place preference suggesting that the reward value of these stimuli is reduced in ArKO males. However, ArKO males showed conditioned place preference when cocaine was used as incentive stimulus, indicating that ArKO males are able to learn the conditioned place preference procedure. These results thus further confirm the important role of estradiol in sexually related behavioral responses in male mice. [less ▲]

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See detailMale aromatase-knockout mice exhibit normal levels of activity, anxiety and "depressive-like" symptomatology
Dalla, C.; Antoniou, K.; Papadopoulou-Daifoti, Z. et al

in Behavioural Brain Research (2005), 163(2), 186-193

It is well known that estradiol derived from neural aromatization of testosterone plays a crucial role in the development of the male brain and the display of sexual behaviors in adulthood. It was ... [more ▼]

It is well known that estradiol derived from neural aromatization of testosterone plays a crucial role in the development of the male brain and the display of sexual behaviors in adulthood. It was recently found that male aromatase knockout mice (ArKO) deficient in estradiol due to a mutation in the aromatase gene have general deficits in coital behavior and are sexually less motivated. We wondered whether these behavioral deficits of ArKO males could be related to changes in activity, exploration, anxiety and "depressive-like" symptomatology. ArKO and wild type (WT) males were subjected to open field (OF), elevated plus maze (EPM), and forced swim tests (FST), after being exposed or not to chronic mild stress (CMS). CNIS was used to evaluate the impact of chronic stressful procedures and to unveil possible differences between genotypes. There was no effect of genotype on OF, EPM and FST behavioral parameters. WT and ArKO mice exposed to CMS or not exhibited the same behavioral profile during these three types of tests. However, all CMS-exposed mice (ArKO and WT) spent less time in the center of the EPM. Additionally, floating duration measured in the FST increased between two tests in both WT and ArKO mice, though that increase was less prominent in mice previously subjected to CNIS than in controls. Therefore, both ArKO and WT males displayed the same behavior and had the same response to CMS however CMS exposure slightly modified the behavior displayed by mice of both genotypes in the FST and EPM paradigms. These results show that ArKO males display normal levels of activity, exploration, anxiety and "depressive-like" symptomatology and thus their deficits in sexual behavior are specific in nature and do not result indirectly from other behavioral changes. (c) 2005 Published by Elsevier B.V. [less ▲]

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See detailMale hypogonadism caused by insolated LH deficiency : From pathology to gene, from gene to physiology
Valdes Socin, Hernan Gonzalo ULg; Salvi, R.; Pralong, F. et al

in 12th International Congress of Endocrinology - Abstract book (2004)

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See detailMale hypogonadism caused by insolated LH deficiency : From pathology to gene, from gene to physiology
Valdes Socin, Hernan Gonzalo ULg; Salvi, R.; Pralong, F. et al

in The 85th Annual Meeting of the Endocrine Society - Abstract book (2003)

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See detailMale hypogonadism caused by insolated LH deficiency : From pathology to gene, from gene to physiology
Valdes Socin, Hernan Gonzalo ULg; Salvi, R.; Pralong, F. et al

in 8th International Pituitary Congress - Abstract book (2003)

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See detailMale hypogonadism caused by isolated LH deficiency : From pathology to gene, from gene to physiology
Valdes Socin, Hernan Gonzalo ULg; Salvi, R.; Pralong, F. et al

in Meeting of the Belgian Endocrine Society : December 2003 (2003, December)

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See detailMale hypogonadism caused by isolated LH deficiency : From pathology to gene, from gene to physiology
Valdes Socin, Hernan Gonzalo ULg; Salvi, R.; Pralong, F. et al

in ENEA congress : Napoli, April 2004 (2004, April)

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See detailMale Hypogonadism caused by isolated luteinizing hormone deficiency
Daly, Adrian ULg; Salvi, R.; Petrossians, Patrick ULg et al

in 37th International symposium - GH and Growth Factors in Endocrinology and Metabolism (Athènes Symposium) (2005)

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See detailMale song quality modulates c-Fos expression in the auditory forebrain of the female canary.
Monbureau, Marie; Barker, Jennifer M.; Leboucher, Gerard et al

in Physiology & behavior (2015), 147

In canaries, specific phrases of male song (sexy songs, SS) that are difficult to produce are especially attractive for females. Females exposed to SS produce more copulation displays and deposit more ... [more ▼]

In canaries, specific phrases of male song (sexy songs, SS) that are difficult to produce are especially attractive for females. Females exposed to SS produce more copulation displays and deposit more testosterone into their eggs than females exposed to non-sexy songs (NS). Increased expression of the immediate early genes c-Fos or zenk (a.k.a. egr-1) has been observed in the auditory forebrain of female songbirds hearing attractive songs. C-Fos immunoreactive (Fos-ir) cell numbers were quantified here in the brain of female canaries that had been collected 30min after they had been exposed for 60min to the playback of SS or NS or control white noise. Fos-ir cell numbers increased in the caudomedial mesopallium (CMM) and caudomedial nidopallium (NCM) of SS birds as compared to controls. Song playback (pooled SS and NS) also tended to increase average Fos-ir cell numbers in the mediobasal hypothalamus (MBH) but this effect did not reach full statistical significance. At the individual level, Fos expression in CMM was correlated with its expression in NCM and in MBH but also with the frequency of calls that females produced in response to the playbacks. These data thus indicate that male songs of different qualities induce a differential metabolic activation of NCM and CMM. The correlation between activation of auditory regions and of the MBH might reflect the link between auditory stimulation and changes in behavior and reproductive physiology. [less ▲]

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