Chantal Lefèbvre

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In recent years, significant progress has been made in understanding cardiomyocyte differentiation. However, little is known about the regulation of myocyte survival despite the fact that myocyte apoptosis is a leading cause of heart failure. Here we report that transcription factor GATA-4 is a survival factor for differentiated, postnatal cardiomyocytes(More)
Activation of mitogen-activated protein kinase (MAPK) in maturing mouse oocytes occurs after synthesis of Mos, a MAPKKK. To investigate whether Mos acts only through MEK1, we microinjected constitutively active forms of MEK1 (MEK1S218D/S222D referred herein as MEK*) and Raf (DeltaRaf) into mouse oocytes. In mos(-/-) oocytes, which do not activate MAPK(More)
We measured lumbar spine, hip (total and sub-regions) and total body bone mineral densities (BMDs) by dual-energy X-ray absorptiometry (DXA) in 47 premenopausal female patients suffering from systemic lupus erythematosus (SLE). As compared to health controls, SLE patients had lower BMDs at all trabecular and cortical sites. Comparison of BMDs between(More)
We reviewed the side-effects of intravenous (i.v.) cyclophosphamide (CPM) pulse therapy in a group of 75 patients suffering from various autoimmune disorders (mostly systemic lupus erythematosus and vasculitis) who received a total of 451 i.v. CPM pulses, given on a monthly basis (mean +/- s.d. CPM dose per pulse: 764 +/- 217 mg; mean +/- s.d. follow-up(More)
Angiotensin II (AII), a potent vasoactive hormone, acts on numerous organs via G-protein-coupled receptors and elicits cell-specific responses. At the level of the heart, AII stimulation alters gene transcription and leads to cardiomyocyte hypertrophy. Numerous intracellular signaling pathways are activated in this process; however, which of these directly(More)
We prospectively followed a cohort of 46 newly diagnosed cases of lupus nephritis (LN) over a mean period of five years in order to determine the renal relapse rate, to identify potential risk factors for relapses, to assess the value of serological tests during flares and to analyse their impact on global outcome. Of the patients 37% experienced at least(More)
In humans, septal defects are among the most prevalent congenital heart diseases, but their cellular and molecular origins are not fully understood. We report that transcription factor Tbx5 is present in a subpopulation of endocardial cells and that its deletion therein results in fully penetrant, dose-dependent atrial septal defects in mice. Increased(More)
We present the case of a 64-year-old previously healthy man admitted for long evoluating fever. Buccal examination showed severe parodontitis. Blood cultures were positive for Leptotrichia buccalis and computed abdominal tomography discovered a hepatic abscess. So far, only exceptional cases of systemic diseases associated with Leptotrichia buccalis(More)
We investigated whether serum titers of interleukin 10 (IL-10), a cytokine known to shift lymphocyte responses towards humoral immunity, reflect disease activity in systemic lupus erythematosus (SLE). Sera from 72 SLE patients, 25 RA patients and 30 healthy controls were tested for IL-10 by ELISA. Low titers of IL-10 were detected in the serum of 37.5% of(More)
OBJECTIVE To evaluate whether bone loss occurs over time in pre-menopausal systemic lupus erythematosus (SLE) patients. METHODS We performed a longitudinal bone mineral density (BMD) analysis in a group of 35 pre-menopausal female SLE patients. Lumbar spine and hip (total and sub-regions) BMDs were measured twice 21 +/- 11 (mean +/- S.D.) months apart by(More)