30 research outputs found

    Immunolocalisation of an ABC transporter, P-glycoprotein, in the eggshells and cuticles of free-living and parasitic stages of <em>Haemonchus contortus</em>

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    International audienceRecent data have suggested that P-glycoprotein (Pgp), working as membrane efflux “pumps”, plays a major role in the transport of anthelmintic drugs in parasitic nematodes of ruminants. Flow cytometry analyses has shown that active Pgp is probably present in the external layers of Haemonchus contortus eggshells, following staining with the mouse monoclonal anti-human MDR1 antibody UIC2, which binds to Pgp in its active conformation. We evaluated the presence and distribution of this protein in the envelopes (eggshells and cuticles) of H. contortus and compared the various stages (eggs, L1–L2 larvae, L3 larvae, adult male and female worms). Electrophoresis revealed a 170-kDa band, corresponding to the molecular weight of Pgp in all stages. Indirect immunofluorescence staining with UIC2 showed Pgp to be located in the external layer of eggshells or cuticles. Transmission electron microscopy was used to localise Pgp more accurately in the three layers of the eggshells and cuticles. The conformation and biological functions of this protein, which we did not expect to find in such structures, remain to be determined

    Sonority as a Phonological Cue in Early Perception of Written Syllables in French

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    International audienceMany studies focused on the letter and sound co-occurrences to account for the well-documented syllable-based effects in French in visual (pseudo)word processing. Although these language-specific statistical properties are crucial, recent data suggest that studies that go all-in on phonological and orthographic regularities may be misguided in interpreting how-and why-readers locate syllable boundaries and segment clusters. Indeed, syllable-based effects could depend on more abstract, universal phonological constraints that rule and govern how letter and sound occur and co-occur, and readers could be sensitive to sonority-a universal phonological element-for processing (pseudo)words. Here, we investigate whether French adult skilled readers rely on universal phonological sonority-related markedness continuum across the syllable boundaries for segmentation (e.g., from marked, illegal intervocalic clusters /zl/ to unmarked, legal intervocalic clusters /lz/). To address this question, we ran two tasks with 128 French adult skilled readers using two versions of the illusory conjunction paradigm (Task 1 without white noise; Task 2 with white noise). Our results show that syllable location and segmentation in reading is early and automatically modulated by phonological sonority-related markedness in the absence or quasi-absence of statistical information and does not require acoustic-phonetic information. We discuss our results toward the overlooked role of phonological universals and the over-trusted role of statistical information during reading processes

    Potential predictors of mean estimated duration for the 8/32-min condition.

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    <p>The predictor is shown along with its associated estimate (coefficient), the confidence interval, the standard errors, <i>t</i>-score and <i>p</i> value.</p

    Potential predictors of passage of time judgment for the 2/8-min condition.

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    <p>The predictor is shown along with its associated estimate (coefficient), the confidence interval, the standard errors, <i>t</i>-score and <i>p</i> value.</p

    Standardized error.

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    <p>Standardized error plotted against interval duration in the 2/8 and the 8/32-min condition.</p

    Potential predictors of mean estimated duration for the 2/8-min condition.

    No full text
    <p>The predictor is shown along with its associated estimate (coefficient), the confidence interval, the standard errors, <i>t</i>-score and <i>p</i> value.</p

    Sinapine, but not sinapic acid, counteracts mitochondrial oxidative stress in cardiomyocytes

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    International audienceIntroduction: When confronted to stress or pathological conditions, the mitochondria overproduce reactive species that participate in the cellular dysfunction. These organelles are however difficult to target with antioxidants. A feature of mitochondria that can be used for this is the negatively charged compartments they form. Most of mitochondrion-targeting antioxidants are therefore cationic synthetic molecules. Our hypothesis is that such mitochondriotropic traits might also exists in natural molecules.Aim: We tested here whether sinapine, a natural phenolic antioxidant-bearing a permanent positive charge, can target mitochondria to modulate mitochondrial oxidative stress.Methods: Experiments were performed in-vitro, in-cellulo, ex-vivo, and in-vivo, using cardiac tissue. The sinapic acid -lacking the positively-charged-choline-moiety present in sinapine-was used as a control. Sinapine entry into mitochondria was investigated in-vivo and in cardiomyocytes. We used fluorescent probes to detect cytosolic (H2DCFDA) and mitochondrial (DHR123) oxidative stress on cardiomyocytes induced with either hydrogen peroxide (H2O2) or antimycin A, respectively. Finally, ROS production was measured with DHE 10 min after ischemia-reperfusion (IR) on isolated heart, treated or not with sinapine, sinapic acid or with a known synthetic mitochondrion-targeted antioxidant (mitoTempo).Results: We detected the presence of sinapine within mitochondria in-vitro, after incubation of isolated cardiomyocytes, and in-vivo, after oral treatment. The presence of sinapic acid was not detected in the mitochondria. Both the sinapine and the sinapic acid limited cytosolic oxidative stress in response to H2O2. Only sinapine was able to blunt oxidative stress resulting from antimycin A-induced mtROS. Both mitoTempo and sinapine improved cardiac functional recovery following IR. This was associated with lower ROS production within the cardiac tissue.Conclusion: Sinapine, a natural cationic hydrophilic phenol, commonly and substantially found in rapeseed species, effectively (i) enters within the mitochondria, (ii) selectively decreases the level of mitochondrial oxidative stress and, (iii) efficiently limits ROS production during cardiac ischemia-reperfusion
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