Publications by authors named "Vigier M"

Docosahexaenoic acid (DHA, C22:6 ω3) may be involved in various neuroprotective mechanisms that could prevent Alzheimer's disease (AD). Its influence has still been little explored regarding the dysfunction of the endolysosomal pathway, known as an early key event in the physiopathological continuum triggering AD. This dysfunction could result from the accumulation of degradation products of the precursor protein of AD, in particular the C99 fragment, capable of interacting with endosomal proteins and thus contributing to altering this pathway from the early stages of AD.

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The orange luminescence of α-AlO under UV excitation is characterized by a 2.07-eV orange broadband emission that has not yet been elucidated. This emission is present in natural and synthetic crystals and powders, as well as in Be-treated samples.

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Using jointly experimental results and first-principles calculations, we unambiguously assign the underlying mechanisms behind two commonly observed luminescence bands for the AlO material. Indeed, we show that the red band is associated with a Ti - transition as expected, while the blue band is the combination of the Ti + O → Ti + O and V+ → V de-excitation processes. Thanks to our recent developments, which take into account the vibrational contributions to the electronic transitions in solids, we were able to simulate the luminescence spectra for the different signatures.

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Although it is clear that people experience physiological arousal in anticipation of news-focused medical consultations, our knowledge of people's experiences during and throughout these consultations is scarce. We examine interbeat interval responses (IBI) of patients and doctors during real-life medical consultations to understand how the experiences of both parties change throughout these encounters and whether they differ from each other. We also examine how the type of news delivered affects responses.

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Perturbations of cholesterol metabolism have been linked to neurodegenerative diseases. Glia-neuron crosstalk is essential to achieve a tight regulation of brain cholesterol trafficking. Adequate cholesterol supply from glia via apolipoprotein E-containing lipoproteins ensures neuronal development and function.

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Most cancer patients exhibit autonomic dysfunction with attenuated heart rate variability (HRV) levels compared to healthy controls. This research aimed to create and evaluate a machine learning (ML) model enabling discrimination between cancer patients and healthy controls based on 5-min-ECG recordings. We selected 12 HRV features based on previous research and compared the results between cancer patients and healthy individuals using Wilcoxon sum-rank test.

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Introduction: Doctors and patients influence each other when interacting and, as a result, can become similar to each other in affect and behavior. In the current work, we examine whether they also become similar to each other on a moment-to-moment basis in their physiological responses. Specifically, we examine physiological linkage-how much a doctor's (or patient's) physiological response predicts a patient's (or doctor's) response at a subsequent time interval-and whether this changes over the course of doctor-patient relationships (measured as the number of consultations held for each unique doctor-patient dyad).

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Environmental contaminants are suspected to be involved in the epidemic incidence of metabolic disorders, food ingestion being a primarily route of exposure. We hypothesized that life-long consumption of a high-fat diet that contains low doses of pollutants will aggravate metabolic disorders induced by obesity itself. Mice were challenged from preconception throughout life with a high-fat diet containing pollutants commonly present in food (2,3,7,8-tetrachlorodibenzo-p-dioxin, polychlorinated biphenyl 153, diethylhexyl phthalate, and bisphenol A), added at low doses in the tolerable daily intake range.

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CD36 is a ubiquitous membrane glycoprotein that binds long-chain fatty acids. The presence of a functional CD36 is required for the induction of satiety by a lipid load and its role as a lipid receptor driving cellular signal has recently been demonstrated. Our project aimed to further explore the role of intestinal CD36 in the regulation of food intake.

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2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) and related substances are ubiquitous environmental pollutants that exert adverse effects on reproductive processes. In testis, Leydig cells which produce testosterone are under hormonal and local control exerted by cytokines including TNFα. Using mouse Leydig primary cell cultures as a model, we studied the effects of TCDD on the steroidogenic outcome of Leydig cells and the gene expression levels of Ccl5 and Cxcl4, previously shown to be target genes of TCDD in testis.

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The hypothalamic melanocortin system--the melanocortin receptor of type 4 (MC4R) and its ligands: α-melanin-stimulating hormone (α-MSH, agonist, inducing hypophagia), and agouti-related protein (AgRP, antagonist, inducing hyperphagia)--is considered to play a central role in the control of food intake. We tested its implication in the mediation of the hunger-curbing effects of protein-enriched diets (PED) in mice. Whereas there was a 20% decrease in food intake in mice fed on the PED, compared to mice fed on an isocaloric starch-enriched diet, there was a paradoxical decrease in expression of the hypothalamic proopiomelanocortin gene, precursor of α-MSH, and increase in expression of the gene encoding AgRP.

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Background: Stem cells and their niches are studied in many systems, but mammalian germ stem cells (GSC) and their niches are still poorly understood. In rat testis, spermatogonia and undifferentiated Sertoli cells proliferate before puberty, but at puberty most spermatogonia enter spermatogenesis, and Sertoli cells differentiate to support this program. Thus, pre-pubertal spermatogonia might possess GSC potential and pre-pubertal Sertoli cells niche functions.

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To study the consequences of maternal obesity during gestation and suckling periods on metabolic features and expression of genes belonging to the melanocortinergic system, we developed Diet-Induced-Obesity (DIO) in mice fed high-fat-diet (HFD). After weaning, F1-descendants were fed the same diet than dams up to 16 weeks or received a 2-week standard chow at several time points. From birth, F1-DIO displayed higher body weight than F1-control.

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Adrenocortical cells of several species have been reported to express significant levels of Agouti-related protein (Agrp) as well as melanocortin 4-receptor (MC4-R). In this study, we used the mouse tumoral adrenal cell line ATC7- L that secretes corticosterone in basal conditions with a 2- fold increase in response to ACTH treatment. We reported that these cells expressed functional MC4-R.

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The objectives of this study were to identify potential alterations in gene expression of melanocortin-4 receptor (MC4-R), proopiomelanocortin (POMC), and Agouti-related protein (AgRP) in mouse hypothalamus under a chronic peripheral infusion of leptin or at early (8 weeks) and advanced (16 weeks) phases of diet-induced obesity. Control or diet-induced obesity mice (8 or 16 weeks of high-fat diet) were either treated or not treated with leptin. Metabolic features were analyzed and expression of the genes of interest was measured by quantitative reverse transcriptase-PCR (RT-qPCR) and western blot.

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IGF-I regulates pituitary and gonadal functions, and is pivotal for sexual development and fertility in mammalian species. To better understand the function of autocrine IGF-I in Sertoli cell physiology, we established a system for Cre-mediated conditional inactivation of the IGF-I receptor (IGF-IR) in cultured Sertoli cells. We show here that loss of IGF-IR decreased the number of viable Sertoli cells as a consequence of diminished Sertoli cell proliferation and increased Sertoli cell death.

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NGF appears to be involved in spermatogenesis. However, mice lacking NGF or TrkA genes do not survive more than a few days whereas p75(NTR) knockout mice are viable and fertile. Therefore, we addressed the effect of betaNGF on spermatogenesis by using the systems of rat germ cell culture we established previously.

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Imatinib combined with high-dose chemotherapy is now becoming the gold standard for treatment of Philadelphia chromosome-positive acute leukemias. However, in all studies imatinib dosage was tapered to 400-600 mg per day. We decided to initiate a clinical trial to evaluate an opposite strategy based on high-dose imatinib (800 mg per day) combined with a less intensive chemotherapeutic regimen (vincristine and dexamethasone), which we called the DIV induction regimen.

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Background: TGF beta and its receptors are present in both germ cells and somatic cells of the male gonad. However, knock-out strategies for studying spermatogenesis regulation by TGF beta have been disappointing since TGF beta-or TGF beta receptor-null mice do not survive longer than a few weeks.

Methods: In the present study, we addressed the role of TGF beta-1 on the completion of meiosis by rat pachytene spermatocytes (PS) cocultured with Sertoli cells.

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The role of FSH and of testosterone in spermatogenesis has been a matter of controversy. In the present study, we addressed the involvement of these hormones in the regulation of the completion of meiosis of male rats under in vitro conditions. In the first series of experiments, middle/late pachytene spermatocytes were cocultured with Sertoli cells for 2 weeks in the absence or presence of FSH and/or testosterone.

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Imatinib mesylate (Gleevec), an inhibitor of the BCR-ABL tyrosine kinase, was introduced recently into the therapy of chronic myeloid leukemia (CML). Several cases of emergence of clonal chromosomal abnormalities after therapy with imatinib have been reported, but their incidence, etiology and prognosis remain to be clarified. We report here a large series of 34 CML patients treated with imatinib who developed Philadelphia (Ph)-negative clones.

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In chronic myelogenous leukemia (CML) imatinib mesylate has been shown to selectively inhibit the tyrosine kinase domain of the oncogenic bcr-abl fusion protein. Using this agent alone high rates of cytogenetic responses were recorded. However, several mechanisms of resistance have been described.

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From 1990 to 1996, a total of 386 adult patients with early/intermediate Hodgkin disease (HD) were randomly assigned to receive 3 cycles of adriamycin, bleomycin, vinblastine, dacarbazine (an alkylating agent), and methylprednisolone (ABVDm, arm A) or epirubicin, bleomycin, vinblastine, methotrexate, and methylprednisolone (EBVMm, arm E), a combination without alkylating agent. Responding patients received extended field radiation therapy (RT). Postchemotherapy complete remission and 10-year freedom from progression rates were higher in arm A (79.

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Imatinib (Gleevec) (formerly STI571) has been shown to selectively inhibit the tyrosine kinase domain of the oncogenic BCR-ABL fusion protein of chronic myelogenous leukemia (CML) cells. In recent phase I and II studies testing this new compound in patients who had failed to respond to interferon (IFN), hematological and cytogenetic responses were reported in most of those with chronic-phase CML. However, in some patients resistance has been associated with a single amino acid substitution in a threonine residue of the Abl kinase domain.

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