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Biomedical subjects

A Bailly

Publications and source records attributed to A Bailly.

At least 19 recordsLinked to original sources
PubMed2005

Double dissociation in neural correlates of visual working memory: a PET study.

Using positron emission tomography (PET), we investigated the organisation of spatial versus object-based visual working memory in 11 normal human subjects. The paradigm involved a conditional colour-response association task embedded within two visual working memory tasks. The subject had to remember a position (spatial) or shape (object-based) and then use this to recover the colour of the matching element for the conditional association. Activation of the nucleus accumbens and the anterior cingulate cortex was observed during the conditional associative task, indicating a possible role of these limbic structures in associative memory. When the 2 memory tasks were contrasted, we observed activation of 2 distinct cortical networks: (1) The spatial task activated a dorsal stream network distributed in the right hemisphere in the parieto-occipital cortex and the dorsal prefrontal cortex, and (2) The non spatial task activated a ventral stream network distributed in the left hemisphere in the temporo- occipital cortex, the ventral prefrontal cortex and the striatum. These results support the existence of a domain-specific dissociation with dorsal and ventral cortical systems involved respectively in spatial and non spatial working memory functions.

Algorithms↗
PubMed2004

Parenteral nutrition practices in hospital pharmacies in Switzerland, France, and Belgium.

OBJECTIVE: Important changes in administering total parenteral nutrition (PN) admixtures have occurred over the past decade. This study describes hospital pharmacists' practices in France (F), Switzerland (CH), and Belgium (B). METHODS: From the responses received using a standardized questionnaire, (n = 378) we determined the origin, types of container used, and choice of PN formula (standard versus tailor-made) and the type of quality control and the existence of nutrition support teams. RESULTS: The mean response rates were 55.6% (CH), 30.5% (F), and 24.5% (B). Standard formulas were used mainly for adult patients (CH, 86%; F, 79%; B, 86%), whereas approximately 50% of tailor-made PN bags were used for children. Single-compartment or multicompartment bags or glass bottles contained standard formulas. Most standard formulas were provided by industry, apart from (B), where 50% of PN solutions were compounded by hospital pharmacies. Single-compartment bags contained generally tailor-made formulas produced exclusively by hospital pharmacies in (CH) and (B), whereas 33% were provided by industry in (F). Quality controls were mostly visual and occurred in 75% to 95% of hospitals. Nutrition support teams were present in 32% to 45% of hospitals. CONCLUSION: The choice, origin, and type of container used for PN formulas were highly variable among countries. However, the use of standard formulas in bags was predominant in (CH) and (B). The function of nutrition support teams was similar in (F), (CH), and (B).

Belgium↗
PubMed2001

An enhancer element 6 kb upstream of the mouse HNF4alpha1 promoter is activated by glucocorticoids and liver-enriched transcription factors.

We have characterized a 700 bp enhancer element around -6 kb relative to the HNF4alpha1 transcription start. This element increases activity and confers glucocorticoid induction to a heterologous as well as the homologous promoters in differentiated hepatoma cells and is transactivated by HNF4alpha1, HNF4alpha7, HNF1alpha and HNF1beta in dedifferentiated hepatoma cells. A 240 bp sub-region conserves basal and hormone-induced enhancer activity. It contains HNF1, HNF4, HNF3 and C/EBP binding sites as shown by DNase I footprinting and electrophoretic mobility shift assays using nuclear extracts and/or recombinant HNF1alpha and HNF4alpha1. Mutation analyses showed that the HNF1 site is essential for HNF1alpha transactivation and is required for full basal enhancer activity, as is the C/EBP site. Glucocorticoid response element consensus sites which overlap the C/EBP, HNF4 and HNF3 sites are crucial for optimal hormonal induction. We present a model that accounts for weak expression of HNF4alpha1 in the embryonic liver and strong expression in the newborn/adult liver via the binding sites identified in the enhancer.

Animals↗
PubMed2000

Discrimination and identification of coastal Douglas-fir clones using needle flavonoid fingerprints.

This paper describes a method for discriminating and identifying 10 successful Douglas-fir (Pseudotsuga menziesii var. menziesii) clones using foliar flavonoids. All the 101 individuals analyzed by high performance liquid chromatography contained two proanthocyanidins: prodelphinidin and procyanidin and six flavonols: myricetin, quercetin, larycitrin, kaempferol, isorhamnetin and syringetin, but in different proportions. The experimental protocol used was very reproducible since the variation coefficients for each flavonoid did not exceed 9%. Submission of the flavonoid data to multivariate discriminant analysis allowed excellent discrimination of the 10 clones with 89% of the individuals being well-grouped. Then a clonal bank was established in which the fingerprint of each clone is defined by its position in the multidimensional space of the discriminant analysis. The clonal identity of several unknown individuals was determined with success by projecting their flavonoid data in a subsequent discriminant analysis.

Journal Article↗
PubMed1998

Phenotypic effects of the forced expression of HNF4 and HNF1alpha are conditioned by properties of the recipient cell.

Tagged versions of HNF4 or HNF1alpha cDNAs in expression vectors have been introduced by transient and stable transfection into three cell lines of hepatic origin that all fail to express these two liver-enriched transcription factors and hepatic functions. C2 and H5 cells are dedifferentiated rat hepatoma variants and WIF12-E cells are human fibroblast-rat hepatoma hybrids with a reduced complement of human chromosomes. Transfectants were analyzed for the expression state of the endogenous genes coding for these transcription factors and for hepatic functions. Each cell line showed a different response to the forced expression of the transcription factors. In C2 cells, no measurable effect was observed, either upon transitory or stable expression. H5 cells reexpressed the endogenous HNF4 gene only upon transient HNF1alpha transfection, and the endogenous HNF1alpha gene only in stable HNF4 transfectants. WIF12-E cells responded to the forced transient or stable expression of either HNF1alpha or HNF4 by cross-activation of the corresponding endogenous gene. In addition, the stable transfectants reexpress HNF3alpha and C/EBPalpha, as well as all of the hepatic functions examined. Hybrid cells similar to WIF12-E had previously been observed to show pleiotropic reexpression of the hepatic phenotype in parallel with loss of human chromosome 2. For the stable WIF12-E transfectants, it was verified that reexpression of the hepatic phenotype was not due to loss of human chromosome 2. The demonstration of reciprocal cross-regulation between HNF4 and HNF1alpha in transient as well as stable transfectants implies that direct effects are involved.

Animals↗
PubMed1995

[The cardiological progression under scrutiny of medicometrics. The case for cardiovascular prevention].

The utility of a new global approach to public health planning, "medicometry", is demonstrated using the example of cardiovascular prevention with its costs and benefits. Although cost-benefit analyses have become plethoric in recent years, they do not give the answers to the right questions asked by a society concerned by the explosion of investments in health care. Medicometry illustrates the complexity of the choices in cardiology and proposes alternative solutions different from simplistic proposals for short term budget cuts. For this demonstration several examples are used: the monetary gains of secondary and primary prevention; the impact of the geographical distribution of physicians on medical utilization; self-control of quality; and the impact of scientific and technologic developments on future costs. The impact of health care choices on the whole of society is stressed. The global feed-back of all medical branches, such as cardiology, is explained taking into account quality-of-life targets and economic, demographic and social constraints.

Cardiovascular Diseases↗
PubMed1994

Phosphorylation sites in ligand-induced and ligand-independent activation of the progesterone receptor.

Steroid hormone receptors are phosphoproteins that undergo hyperphosphorylation upon binding of hormone. The mechanism and the role of this reaction remain poorly understood. Two-dimensional analysis of ligand-free progesterone receptor (PR) tryptic digests showed the existence of seven main phosphopeptides. Incubation of the cells with the progestin R5020 led to a global increase in the levels of PR phosphorylation. However, the same phosphopeptides were seen, and their levels of labeling relative to each other were unchanged. A similar result was observed after incubation of cells with the antiprogestin RU486. The antiprogestin ZK98299 demonstrated only half of the activity of RU486 in terms of receptor hyperphosphorylation, but the same phosphopeptides, proportionally labeled to the same extent, were observed by chromatography electrophoresis. Ligand-induced DNA binding did not play a role in receptor hyperphosphorylation since the mutant delta 547-592, which is devoid of the first zinc finger region, exhibited the same phosphopeptides, labeled to the same extent, as did wild-type receptor after incubation of cells with hormone. These results suggest that the same kinase(s) act in vivo on ligand-free and on agonist or antagonist-bound progesterone receptor. Binding of different ligands produces different conformational changes in the ligand binding domain of the receptor which enhance, to varying extents, affinity of the receptor for the kinase(s). The DNA binding region also plays a role in the interaction with the kinase(s), although binding to DNA per se is not necessary for the hyperphosphorylation of the receptor to take place.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

The progesterone receptor. Biological effects of progestins and antiprogestins.

The progesterone receptor displays the typical three-domains structure of the steroid-thyroid receptor family. The central domain contains two 'zinc finger' structures responsible for the specific recognition of the cognate DNA sequences. The carboxy-terminal domain contains the hormone and anti-hormone binding site. Progesterone and synthetic progestins (R5020, Org 2058) activate the receptor, provoke its phosphorylation and DNA-binding ability and induce its regulatory activities. The antagonist RU38486 elicits the same sequence of events but leads to an abortive conclusion without specific gene transactivation. The progesterone receptor is down-regulated by its own ligand at the transcriptional level through inhibition of oestrogen receptor-mediated induction through protein-protein interactions. This mechanism is also inhibited by RU38486.

Animals↗
PubMed1993

Specific binding of progesterone receptor to progesterone-responsive elements does not require prior dimerization.

Steroid-hormone receptors undergo, prior to binding to DNA, a hormone-dependent dimerization. It is generally accepted that this dimerization is indispensable for the high-affinity binding of hormone receptor to hormone-responsive elements. Using a progesterone-receptor mutant with the complete steroid-binding domain deleted (positions 663-930), with or without the epitope required for binding the monoclonal antibody Let 126, we have shown that this receptor species was unable to undergo dimerization in solution. However, this mutant retained a high affinity (60-70% of the affinity of the wild-type receptor) for the progesterone-responsive elements of the mouse-mammary-tumor-virus long-terminal-repeat promoter and for a consensus palindromic progesterone-responsive element, as measured by both DNase-I protection experiments and gel-shift experiments. This mutant also increased gene transcription. Thus, at least in the case of the progesterone receptor, prior dimerization is dispensable for receptor binding to regulatory DNA elements and for subsequent transcription activation.

Animals↗
PubMed1992

Failure of thiamphenicol in a penicillin-allergic patient with Listeria meningoencephalitis--delayed cure following penicillin desensitization.

A 27-year-old woman, without compromised immunodefenses, experienced a Listeria meningoencephalitis, with brainstem symptoms. The identified agent exhibited poor susceptibility to usual effective antibiotics, except for penicillins. Knowledge of past history of an allergic reaction to beta-lactam antibiotics lead to appropriate therapy after acute intravenous desensitization of the patient to amoxicillin. Treatment resulted in therapeutic administration rate over 24 h, and in rapid regression of clinical and biological disorders.

Adult↗
PubMed1991

Characterization of the hormone responsive element involved in the regulation of the progesterone receptor gene.

The transcription of the progesterone receptor gene is induced by estrogens and decreased by progestins. Studies were performed to define the regions of the gene and the molecular mechanisms involved. No hormonal regulation could be observed using 5' flanking regions of the gene up to -2762 in front of a heterologous gene. Estrogen and progestin regulation could be observed only when using fragments of the gene extending down to +788. Progressive deletions from the 5' and 3' ends, site-directed mutagenesis and DNase protection experiments with purified estrogen receptor suggested that the biologically active estrogen responsive element (ERE) is present at +698/+723, overlapping the initiation of translation. An oligonucleotide was synthesized bearing this ERE and shown to impart estrogen inducibility to a heterologous gene. Its regulation by anti-estrogens corresponded to that of the in situ progesterone receptor gene since tamoxifen was a partial agonist whereas ICI 164384 was a full antagonist. This ERE also mediated down-regulation by progestins in the presence of the progesterone receptor, even though it has no progesterone receptor binding ability. DNase footprinting showed that this effect was not due to a decrease of estrogen receptor affinity for the ERE in the presence of progesterone receptor. Finally, use of deletion mutants of the progesterone receptor showed that the steroid binding and the DNA binding domains were necessary for down-regulation whereas deletions of various parts of the N-terminal domain were without effect.

Animals↗
PubMed1991

Post-transcriptional analysis of rat mitochondrial D-3-hydroxybutyrate dehydrogenase control through development and physiological stages.

The nuclear encoded mitochondrial D-3-hydroxybutyrate dehydrogenase (BDH) is synthesized in the cytosal as a larger precursor. This membrane enzyme which requires lecithin for activity plays an essential role in energy metabolism as a ketone bodies-converting enzyme. A cDNA clone of the rat liver enzyme encompassing an antigenic determinant peptide has been isolated after immunoscreening of a lambda gt11 expression library. The nucleotide sequence of this 279-base cDNA insert contains a single open reading frame of 93 amino-acids, which represents about a third of the mature enzyme. Amino-acid sequence analysis predicts a hydrophobic stretch of 29 amino-acids long which probably functions as membrane anchor domain, or as an important region for the enzyme activation by phospholipid. By using this cDNA probe the BDH gene has been investigated at the mRNA level. There is only one mRNA (2-kb size) for BDH whatever the studied tissue. The rat gene is differently expressed since its mRNA is already present in the foetus liver while the BDH polypeptide amount is low and its enzymatic activity is not detectable even in the late stage of foetal development. The mRNA content is higher in the liver than in extrahepatic tissues. Adrenalectomy and ovariectomy increase liver mRNA content and polypeptide level, as well as activity of BDH. These effects are totally or partially abolished by corticosterone and estradiol treatments respectively. In addition, a 15-day hyperlipidic diet stimulates BDH gene expression. Present results show that the gene expression of this mitochondrial enzyme is modulated through development and hormonal and metabolic conditions mentioned above.

Aging↗
PubMed1991

In two genes, synergism of steroid hormone action is not mediated by cooperative binding of receptors to adjacent sites.

Synergistic action of multiple steroid hormone response elements (HREs) has been proposed to be due to cooperative binding of receptors. We have studied the cooperativity of steroid hormone receptor binding to synergistic HREs in two natural genes. In the mouse mammary tumor virus long terminal repeat that contains four progesterone receptor binding sites, no cooperativity in receptor binding was observed between the single distal and the three proximal sites whereas a low level of cooperativity in receptor binding (about 2-fold) was found between the three proximal sites. This contrasted with the very strong synergism of these four HREs in stimulation of transcription. In the chicken vitellogenin II gene upstream sequences, an estrogen and a progestin response elements act synergistically. In this case again, no cooperativity of binding of the estrogen and progesterone receptors to their respective binding sites was observed. We therefore conclude that cooperative receptor binding may not always be required for synergistic action of multiple HREs.

Animals↗
PubMed1990

Variations of specific mRNA and polypeptide contents of rat liver D-beta-hydroxybutyrate dehydrogenase during an experimental diabetes mellitus.

The expression of the rat liver D-beta-hydroxybutyrate dehydrogenase (BDH) gene was investigated at different levels: the level of its specific mRNA, the protein content and the enzymatic activity. By using a cDNA probe, we found that the BDH mRNA was about 2 kb and we report here that the decrease of BDH activity in diabetic rats is due to a reduction in the content of the enzyme, which is proportional to a diminution in the amount of the BDH mRNA. We also show that insulin is able to reverse this diabetes effect by restoring the level of BDH mRNA, the BDH content and thus its activity. This result indicates that in vivo the control of the expression of the BDH gene by insulin is mainly transcriptional and/or post-transcriptional (mRNA stability).

Animals↗
PubMed1990

Structural and functional studies of mammalian progesterone receptors.

During the past years there has been an improvement in our understanding of the molecular mechanism of action of the progesterone receptor (PR). This was due to the obtention of monoclonal antibodies against PR which allowed the first structural analyses and led to the cloning of the genes.

Animals↗
PubMed1989

Immunoreactive somatomedin C in children from Morocco: a biological marker of nutritional growth retardation?

Somatomedin C (Sm-C) is supposed to be a sensitive marker of malnutrition. Its relationship to growth and protein intake was investigated in 47 Moroccan children. The children (mean age: 7.5 +/- 2 yr) had no endocrine abnormality. Anthropometric parameters were measured, together with blood levels of Sm-C and growth hormone (GH). Lower values of Sm-C were found in the following situations: (a) growth retardation (more than -2 Sd, N = 23; Sm-C = 3.61 +/- 0.42 nmol/l vs. 13.38 +/- 1.52, P less than 0.02); (b) body weight less than 80% of expected weight for height (N = 8; Sm-C = 4.84 +/- 0.97 vs. 10.33 +/- 1.19, P less than 0.02); (c) boys with meat consumption less than 3 times per wk (N = 15; Sm-C = 4.03 +/- 0.71 vs. 12.35 +/- 2.01, P less than 0.002). Thus, lower values of Sm-C are found in association with weight insufficiency and lower protein intake. As has previously been assumed, serum Sm-C, which is regulated by nutrition, may be a sensitive tool in the assessment of nutritional status in developing countries such as Morocco. Furthermore, it could explain some cases of growth retardation in states of malnutrition.

Adolescent↗