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Biomedical subjects

M Bernard

Publications and source records attributed to M Bernard.

At least 37 records · Page 2Linked to original sources
PubMed2004

Dose dependent accretion of docosahexaenoic acid (DHA) in cardiac membranes of rats fed egg yolk powder enriched in DHA.

We tested the hypothesis that enrichment of the diet with docosahexaenoic acid (DHA) enriched egg yolk powder could modify specifically the (n-3) fatty acids content of rat plasma, red blood cells and heart membranes. Dose-dependent effect of DHA was studied in rats supplemented during 4 weeks. Three groups of adult male rats, DHA10, DHA35 and DHA60 (n = 5 each), had their diet supplemented with 10 mg, 35 mg or 60 mg DHA/kg body weight/day, respectively. Fatty acid composition of membranes and plasma lipids were determined. A significant dose-dependent increase in DHA was observed in all three types of samples. Arachidonic acid (AA) levels did not change in heart and red blood cell membranes whereas it increased significantly in plasma with the DHA35 diet. These results contrast with that previously reported for fish oil supplementation where a decrease in AA levels was reported. Hence, DHA enriched egg yolk supplementation leads to a specific accretion of DHA without competition on AA status.

Animals↗
PubMed2003

Preservation of amino acids during long term ischemia and subsequent reflow with supplementation of L-arginine, the nitric oxide precursor, in the rat heart.

We investigated whether L-arginine, used in heart preservation to limit endothelial damage, may influence the pool of amino acids during long term ischemia and reflow. Isolated isovolumic rat hearts (n = 23) were submitted to 8 h of hypothermic ischemia after cardioplegic arrest with the Centre de Résonance Magnétique Biologique et Médicale (CRMBM) solution with or without L-arginine (Arg and No Arg groups respectively). Hearts were freeze-clamped after ischemia (n = 11) or submitted to 60 min of reflow (n = 12) and freeze-clamped. Eight hearts were perfused aerobically for 20 min and freeze-clamped (No ischemia group). Addition of L-arginine to the CRMBM solution limited aspartate depletion and decreased lysine level at the end of ischemia. After reflow, L-arginine supplementation increased the pool of glutamate and arginine and limited the depletion of serine, asparagine, glycine and taurine. We conclude that adding L-arginine to the CRMBM cardioplegic solution during long term ischemia preserved the amino acids pool.

Amino Acids↗
PubMed2003

A fluorescence microplate assay using yopro-1 to measure apoptosis: application to HL60 cells subjected to oxidative stress.

A new one-step labeling procedure using the membrane permeant fluorescent probe yopro-1 in association with fluorescence microtitration for the rapid determination of apoptosis is reported. Programmed cell death was induced by the pro-apoptotic agents etoposide and staurosporine, and measured in nonadherent HL60 cells and adherent phorbol 12-myristate 13-acetate (PMA)-treated HL60 cells. Cell viability was controlled by trypan blue exclusion and calcein-AM staining. To confirm results of fluorescence microplate assay, apoptosis was measured by flow cytometry analysis using the same fluorescent probe, and results showed corresponding data between both procedures. Development of apoptosis was confirmed by the presence of PARP (poly(ADP-ribose) polymerase cleavage and nuclear DAPI (4,6-diamidino-2-phenylindole) staining, two well-known methods used to investigate apoptosis. The fluorescence microplate assay was also applied to measure apoptosis in cells exposed to an oxidative stress induced by tert-butylhydroperoxide (t-BHP), and results confirmed the potential of the fluorescence microplate assay in measuring events of apoptosis, especially in adherent, cultured, living cells.

Apoptosis↗
PubMed2003

Nervous system lymphoid infiltration in Waldenström's macroglobulinemia. A case report.

Neurological complications may occur in the course of Waldenström's macroglobulinemia (Wm). These complications affect both the central and peripheral nervous system. Pathogenesis is debated and several mechanisms have been suggested. Direct malignant lymphoid infiltration (MLI) is very rare and has only been reported in a few cases. Case report. A 67-year-old woman suffered from Wm for 10 years before she presented neurological complications of the disease. She did not receive any specific treatment for Wm owing to a lack of symptoms. The neurological complications consisted of peripheral demyelinating polyneuropathy and MLI of the nervous system. This infiltration was located in the lower perimedullary and cauda equina roots regions, with possible centromedullary involvement. Indirect demonstration of MLI was achieved through non-invasive tests including magnetic resonance imaging and detailed cerebrospinal fluid examination. General and intrathecal chemotherapy led to clinical, biological and radiological improvement over a four-year period.

Acute Disease↗
PubMed2003

Large scale validation of human N-myc downstream-regulated gene (NDRG)-1 expression in endometrium during the menstrual cycle.

A major challenge in the comprehension of the endometrial transformations leading to the completion of each menstrual cycle in humans is in the identification of specific molecular pathways underlying these monthly turnovers. Towards this goal we compared, by the differential display technique, the relative expression of mRNA in endometrial biopsies harvested in individuals (n = 48) either at the proliferative or the secretory phase of the menstrual cycle. We isolated a cDNA fragment homologous to NDRG1 (N-myc Downstream-Regulated Gene-1) that is present in markedly higher amounts in the secretory phase. Northern blot analysis and quantitative real time PCR experiments confirmed this result in distinct cohorts of individuals (44 and 560 respectively). A closer examination of data showed that the highest mRNA levels were found during the range of 25-28 days of the uterine cycle. Consistent with the mRNA data, the temporal profile of the NDRG1 protein showed a 15-fold increase during the secretory phase, as demonstrated by using semi-quantitative dot blot analyses (n = 92). Immunohistochemical localization revealed that NDRG1 was expressed both in epithelial and stromal cells. This large scale validation of the NDRG1 mRNA and protein increase in endometrium during the secretory phase is consistent with its differentiation-related function described in other tissues and its potential involvement in the window of implantation of the human endometrium, as suggested by previous chip-based evidence.

Base Sequence↗
PubMed2003

[Radiological spectrum of myositis ossificans circumscripta evolution].

Myositis ossificans circumscripta is a benign pathology of soft tissue occurring in young patients often after localized trauma. Histological and radiological appearances may mimic a malignant neoplasm, mainly sarcoma. We report a case characteristic of myositis ossificans circumscripta, to illustrate diagnostic arguments which are based on their appearance on conventional radiographs, computed tomography and magnetic resonance imaging and on their changes with time.

Adult↗
PubMed2002

Structural organization of the group-1 chromosomes of two bread wheat sister lines.

Eureka and Renan are two French bread wheat cultivars derived from a 4-way cross. Using molecular markers (essentially RFLPs), we studied the structure of the group-1 chromosomes of these two genotypes, their parents and a doubled-haploid (DH) population derived from their F(1). Using the DH population (102 lines), a molecular map of the three homoeologous group-1 chromosomes was produced and compared with the map established on another intervarietal cross: Courtot x Chinese Spring (Cadalen et al. 1997). The polymorphic markers were mapped on the DH population and characterized on the four grand-parents, allowing us to compare the structural organization of the group-1 chromosomes of Eureka and Renan and determine their origin. These chromosomes were very different, except for small regions (1AL proximal and 1BL distal) which were identical.

Biological Evolution↗
PubMed2002

An update of the Courtot x Chinese Spring intervarietal molecular marker linkage map for the QTL detection of agronomic traits in wheat.

We made an update of the intervarietal molecular marker linkage map of the wheat genome developed using a doubled-haploid (DH) population derived from the cross between the cultivars "Courtot" and "Chinese Spring". This map was constructed using 187 DH lines and 659 markers. The genome was well covered (more than 95%) except for chromosomes from homoeologous group 4 and chromosomes 5D and 7D, which had gaps slightly larger than 50 cM. A core-map based on a set of 200 anchor loci (one marker each 18.4 cM) was developed. The total length of this map was 3,685 cM which is similar to the size of the international reference map of the ITMI population (3,551 cM). Map coverage was identical for the three genomes (A, B and D) and for the number of anchor loci, as well as for the size of the map. Using this map, QTLs for several agronomic traits were detected on phenotypic data from the population grown in Clermont-Ferrand (France) under natural field conditions over 6 years, and in Norwich (UK) in controlled conditions and under natural field conditions in 1 year. Almost all of the 21 chromosomes were involved in at least one trait. However, several regions seemed to contain gene clusters either for grain traits (and thus bread-making quality) or plant development traits.

Chromosome Mapping↗
PubMed2002

Usefulness of procalcitonin as a marker of systemic infection in emergency department patients: a prospective study.

We prospectively evaluated serum procalcitonin concentrations in patients who presented to an emergency department (ED) with suspected infectious or inflammatory disease. Of 195 study patients, 68 had final diagnosis of systemic infection, and 24 of those 68 had elevated serum procalcitonin levels (>0.5 ng/mL). The procalcitonin level had a sensitivity of 0.35 and specificity of 0.99 for the diagnosis of systemic infection. In multivariate analysis, the procalcitonin level was the only independent variable associated with this diagnosis; in contrast, the C-reactive protein level was not. All patients with systemic infections who ultimately died had procalcitonin levels of >0.5 ng/mL at admission. Procalcitonin levels were significantly higher in patients who ultimately died of systemic infection than in patients who survived. The optimal procalcitonin threshold for the ED population may be lower than that proposed for critically ill patients. Determination of the procalcitonin level may be useful for screening and prognosis of more-severely ill ED patients.

Adolescent↗
PubMed2002

Study of the relationship between pre-harvest sprouting and grain color by quantitative trait loci analysis in a whitexred grain bread-wheat cross.

In many wheat ( Triticum aestivumL.) growing areas, pre-harvest sprouting (PHS) may cause important damage, and in particular, it has deleterious effects on bread-making quality. The relationship between PHS and grain color is well known and could be due either to the pleiotropic effect of genes controlling red-testa pigmentation ( R) or to linkage between these genes and other genes affecting PHS. In the present work, we have studied a population of 194 recombinant inbred lines from the cross between two cultivars, 'Renan' and 'Récital', in order to detect QTLs for both PHS resistance and grain color. The variety 'Renan' has red kernels and is resistant to PHS, while 'Récital' has white grain and is highly susceptible to PHS. A molecular-marker linkage map of this cross was constructed using SSRs, RFLPs and AFLPs. The population was evaluated over 2 years at Clermont-Ferrand (France). PHS was evaluated on mature spikes under controlled conditions and red-grain color was measured using a chromameter. Over the 2 years, we detected four QTLs for PHS, all of them being co-localized with QTLs for grain color. Three of them were located on the long arm of chromosomes 3 A, 3B and 3D, close to the loci where the genes R and taVp1 were previously mapped. For these three QTLs, the resistance to PHS is due to the allele of the variety 'Renan'. Another co-located QTL for PHS and grain color was detected on the short arm of chromosome 5 A. The resistance for PHS for this QTL is due to the allele of 'Récital'.

Journal Article↗
PubMed2002

High multidrug resistance protein activity in acute myeloid leukaemias is associated with poor response to chemotherapy and reduced patient survival.

Multidrug resistance protein (MRP) activity was investigated in 44 newly diagnosed acute myeloid leukaemia (AML) patients using a functional assay based on efflux of carboxy-2',7'-dichlorofluorescein, an anionic dye handled by both MRP1 and MRP2. Elevated MRP transport was detected in 29% of cases, but was not significantly correlated with sex, age, white blood cell count at diagnosis or karyotype. In contrast, it was associated with secondary AML (P = 0.002), CD34 positivity (P = 0.041) and P-glycoprotein activity (P = 0.01). There was a lower rate of complete remission in MRP-positive patients versus MRP-negative patients (23% versus 81%; P = 0.001); overall survival was also better for MRP-negative patients (P = 0.004). These data indicate a probable role for MRP activity in the clinical outcome of AML.

ATP Binding Cassette Transporter, Subfamily B↗
PubMed2001

Proteome analysis of Aspergillus fumigatus identifies glycosylphosphatidylinositol-anchored proteins associated to the cell wall biosynthesis.

Previous studies in Aspergillus fumigatus (Mouyna I., Fontaine T., Vai M., Monod M., Fonzi W. A., Diaquin M., Popolo L., Hartland R. P., Latgé J.-P, J. Biol. Chem. 2000, 275, 14882-14889) have shown that a glucanosyltransferase playing an important role in fungal cell wall biosynthesis is glycosylphosphatidylinositol (GPI) anchored to the membrane. To identify other GPI-anchored proteins putatively involved in cell wall biogenesis, a proteomic analysis has been undertaken in A. fumigatus and the protein data were matched with the yeast genomic data. GPI-anchored proteins of A. fumigatus were released from membrane preparation by an endogenous GPI-phospholipase C, purified by liquid chromatography and separated by two-dimensional electrophoresis. They were characterized by their peptide mass fingerprint through matrix-assisted laser desorption/ionization-time of flight-(MALDI-TOF)-mass spectrometry and by internal amino acid sequencing. Nine GPI-anchored proteins were identified in A. fumigatus. Five of them were homologs of putatively GPI-anchored yeast proteins (Csa1p, Crh1p, Crh2p, Ecm33p, Gas1p) of unknown function but shown by gene disruption analysis to play a role in cell wall morphogenesis. In addition, a comparative study performed with chitin synthase and glucanosyl transferase mutants of A. fumigatus showed that a modification of the growth phenotype seen in these mutants was associated to an alteration of the pattern of GPI-anchored proteins. These results suggest that GPI-anchored proteins identified in this study are involved in A. fumigatus cell wall organization.

Animals↗
PubMed2001

Simultaneous study of metabolism and function following cardioplegic arrest: a novel method of evaluation of the transplanted heart in the rat.

BACKGROUND: Limitations of the isolated perfused rat heart model for heart preservation studies include short study time due to the lack of stability of the preparation. We aimed to develop a new experimental model based on heterotopic heart transplantation in the rat to achieve simultaneous (31)P magnetic resonance spectroscopy (MRS) and functional study of the transplanted heart during early and late blood reperfusion. METHODS: Twenty-five Lewis rats underwent heterotopic abdominal isograft heart transplantation and were randomized in two groups. Hearts were harvested after cardioplegic arrest induced with Centre de Résonance Magnétique Biologique et Médicale (CRMBM) solution and then stored at 4 degrees C for a total ischemic time of 3 hours. Graft contractility measurement and simultaneous (31)P MRS were performed after 1 hour and 24 hours of blood reperfusion, respectively, in groups I (n = 12) and II (n =13). RESULTS: Contractility improved during reperfusion. The mean rate pressure product plus or minus standard error of mean increased from 11,373 +/- 1,377 mm Hg/min in group I to 24,363 +/- 3,860 mm Hg/min in group II (P = 0.003), while mean dP/dtmax increased from 1,642 +/- 173 mm Hg/sec to 2,571 +/- 333 mm Hg/sec, respectively (p = 0.03). Simultaneously, both the phosphocreatine/adenosine triphosphate (ATP) and inorganic phosphate/ATP ratios decreased from group I to group II (p = 0.025 and p = 0.015, respectively), suggesting regeneration of the intracellular pool of ATP in group II. CONCLUSIONS: Simultaneous functional and metabolic studies of the transplanted heart are feasible in rats. Improvement in contractility during late reperfusion is contemporary with significant changes in energetic metabolism. Our model should be useful for the further improvement of heart preservation, which may result in significant clinical progress.

Adenosine Triphosphate↗
PubMed2001

Primary isolated lymphoma of the fourth ventricle: case report.

The authors present the case of a 33-year-old woman presenting with a 4-week history of vertigo and headaches. Physical examination revealed an isolated static cerebellar syndrome. Magnetic resonance imaging showed a homogeneously enhancing tumor located in the fourth ventricle. Complete surgical removal was performed and microscopic examination revealed a high-grade B-cell lymphoma. Postoperative investigations confirmed it to be primary. Only one case of primary isolated lymphoma of the fourth ventricle has been briefly reported in the medical literature. The authors suggest that primary lymphoma must be considered in the list of fourth ventricle tumors.

Adult↗