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Biomedical subjects

M Carrière

Publications and source records attributed to M Carrière.

14 recordsLinked to original sources
PubMed2007

Development of a single ion hit facility at the Pierre Sue Laboratory: a collimated microbeam to study radiological effects on targeted living cells.

A single ion hit facility is being developed at the Pierre Süe Laboratory (LPS) since 2004. This set-up will be dedicated to the study of ionising radiation effects on living cells, which will complete current research conducted on uranium chemical toxicity on renal and osteoblastic cells. The study of the response to an exposure to alpha particles will allow us to distinguish radiological and chemical toxicities of uranium, with a special emphasis on the bystander effect at low doses. Designed and installed on the LPS Nuclear microprobe, up to now dedicated to ion beam microanalysis, this set-up will enable us to deliver an exact number of light ions accelerated by a 3.75 MV electrostatic accelerator. An 'in air' vertical beam permits the irradiation of cells in conditions compatible with cell culture techniques. Furthermore, cellular monolayer will be kept in controlled conditions of temperature and atmosphere in order to diminish stress. The beam is collimated with a fused silica capillary tubing to target pre-selected cells. Motorisation of the collimator with piezo-electric actuators should enable fast irradiation without moving the sample, thus avoiding mechanical stress. An automated epifluorescence microscope, mounted on an antivibration table, allows pre- and post-irradiation cell observation. An ultra thin silicon surface barrier detector has been developed and tested to be able to shoot a cell with a single alpha particle.

Cell Culture Techniques↗
PubMed2006

Low density lipoprotein receptor transcripts correlates with liver hepatitis C virus RNA in patients with alcohol consumption.

Alcohol consumption has a major impact on the natural history of chronic hepatitis C virus (HCV) infection, although the underlying mechanisms are still debated. We designed a clinical study to evaluate the impact of alcohol abuse on both viral load and expression of low-density lipoprotein receptor (LDLR) and CD81 expression. Thirty-eight consecutive HCV-infected patients were enrolled. Group 1 (n = 18), < or =10 g alcohol/day, group 2 (n = 8), < or =30 g alcohol/day, group 3 (n = 12), >or =30 g alcohol/day. Receptors expression was measured by flow cytometry analysis in peripheral blood mononuclear cells (PBMC) and by specific real-time retrotranscription polymerase chain reaction (RT-PCR) in the liver. Serum viral load was evaluated by quantification of both HCV genomic RNA and total core antigen. The hepatic viral load was assessed by real-time RT-PCR. Serum HCV-RNA and total core antigen were significantly correlated, and were higher, albeit not significantly, in group 3 than in group 1. Alcohol consumption had no effect on expression of HCV putative receptors in PBMC, except for CD81, which was upregulated on monocytes in group 2. In the liver, viral load and levels of LDLR transcripts were significantly higher in group 3 than in group 1. Remarkably, a significant positive correlation was found between LDLR transcripts and HCV-RNA (r2 = 0.83, P < 10(-3)). Finally, in vitro experiments suggested that the effect of ethanol on LDLR expression was indirectly mediated by both tumour necrosis factor-alpha and interleukin-1beta. In conclusion, this study is the first to support a role for LDLR in the natural infection by HCV in man.

Adult↗
PubMed2004

[Sneddon-Wilkinson disease. Four cases report].

INTRODUCTION: We report four cases of subcorneal pustular dermatosis or Sneddon-Wilkinson disease. Clinical and histological lesions and immunofluorescence data were presented. This disease is classified among neutrophilic dermatitis. PATIENTS AND METHODS: All of four patients presented with clinical and histological lesions compatible with the diagnosis of Sneddon-Wilkinson disease. Indeed, direct and indirect immuno-testing were negative. We noted an association with a benign IgA monoclonal gammapathy in one case and with a seronegative polyarthritis in one other case. Three patients correctly responded to dapsone. One of them after transient improvement was resistant to dapsone and then dramatically responded to etretinate. CONCLUSION: Subcorneal pustular dermatosis is a chronic disease, rarely described in literature. It's a pustular eruption, involving the trunck, axillae and inguinal holds. It's often associated with monoclonal gammapathy, particulary IgA. Its nosological situation is still contested, especially with IgA pemphigus sharing with it the association with IgA monoclonal gammapathy and the same efficacy of dapsone. We discuss relationships between both diseases.

Aged↗
PubMed2004

Influence of uranium speciation on normal rat kidney (NRK-52E) proximal cell cytotoxicity.

Uranium is a naturally occurring heavy metal. Its extensive use in the nuclear cycle and for military applications has focused attention on its potential health effects. Acute exposures to uranium are toxic to the kidneys where they mainly cause damage to proximal tubular epithelium. The purpose of this study was to investigate the biological consequences of acute in vitro uranyl exposure and the influence of uranyl speciation on its cytotoxicity. NRK-52E cells, representative of rat kidney proximal epithelium, were exposed to uranyl-carbonate and -citrate complexes, which are the major complexes transiting through renal tubules after acute in vivo contamination. Before NRK-52E cell exposure, these complexes were diluted in classical or modified cell culture media, which can possibly modify uranyl speciation. In these conditions, uranium cytotoxicity appears after 16 h of exposure. The CI50 cytotoxicity index, the uranium concentration leading to 50% dead cells after 24 h of exposure, is 500 microM (+/-100 microM) and strongly depends on uranyl counterion and cell culture medium composition. Computer modeling of uranyl speciation is reported, enabling one to draw a parallel between uranyl speciation and its cytotoxicity.

Animals↗
PubMed2000

The utilization of recombinant prostanoid receptors to determine the affinities and selectivities of prostaglandins and related analogs.

Stable cell lines that individually express the eight known human prostanoid receptors (EP(1), EP(2), EP(3), EP(4), DP, FP, IP and TP) have been established using human embryonic kidney (HEK) 293(EBNA) cells. These recombinant cell lines have been employed in radioligand binding assays to determine the equilibrium inhibitor constants of known prostanoid receptor ligands at these eight receptors. This has allowed, for the first time, an assessment of the affinity and selectivity of several novel compounds at the individual human prostanoid receptors. This information should facilitate interpretation of pharmacological studies that employ these ligands as tools to study human tissues and cell lines and should, therefore, result in a greater understanding of prostanoid receptor biology.

Binding, Competitive↗
PubMed1999

A family of Arabidopsis plasma membrane receptors presenting animal beta-integrin domains.

A cDNA clone, AtELP1 (Arabidopsis thaliana EGF receptor-like protein) was isolated from an Arabidopsis cDNA library with an oligonucleotide probe corresponding to a highly conserved region of animal beta-integrins. The cloning of this cDNA was previously reported and it has been proposed that AtELP might be a receptor involved in intracellular trafficking. In the present work, using two specific independent sets of anti-peptide antibodies, we show that AtELP1 is mainly located in the plasma membrane, supporting another function for this protein. Structural studies, using methods for secondary structure prediction, indicated the presence of cysteine-rich domains specific to beta-integrins. Database searches revealed that AtELP1 is a member of a multigenic family composed of at least six members in A. thaliana. Northern blot analysis of AtELP1, 2b and 3 was performed on mRNA extracted from cells cultured in normal and stressed conditions, and from several organs and plants submitted to biotic or abiotic stresses. All the genes are expressed at different levels in the same conditions, but preferentially in roots, fruits and leaves in response to water deficit.

Amino Acid Sequence↗
PubMed1999

Construction of two ordered cDNA libraries enriched in genes encoding plasmalemma and tonoplast proteins from a high-efficiency expression library.

We constructed a high-efficiency expression library from Arabidopsis cDNA clones by introducing a poly (dC) stretch at the 5' end of the clones. This library enables the synthesis of proteins from all the cDNA clones present. We have screened the high-efficiency expression library with antibodies raised against total proteins from Arabidopsis plasmalemma and tonoplast. With the positive clones, we have constructed two cDNA ordered libraries enriched in genes encoding plasmalemma (522 clones) and tonoplast proteins (594 clones). Partial sequencing of both libraries shows that a high proportion (47%) of the clones encoded putative membrane proteins, or membrane-associated proteins. When sequenced, 55% of the cDNAs were new EST sequences for Arabidopsis, 26% were similar to genes present in other plants or organisms, and 29% were not referenced in any databank. Immunoscreening of the two cDNA ordered libraries with antibodies raised against proteins from Arabidopsis cells submitted to osmotic stress allows the selection of genes over- and under-expressed in stress conditions.

Arabidopsis↗
PubMed1983

[An amnesic adolescent].

Personality amnesia is a difficult and fairly uncommon problem in psychiatric practice. We report the case of a 15-year-old adolescent who experienced total amnesia for two months. His identity could be established only by publishing his photo and history in a widely read newspaper. After discussing diagnostic problems, we remain unsure as to the psychopathological diagnosis, a difficult issue in personality amnesia, and prognosis, which is unpredictable as a result of the changes inherent to adolescence.

Adolescent↗
PubMedDate not supplied

Critical assessment of the nuclear import of plasmid during cationic lipid-mediated gene transfer.

BACKGROUND: Cationic lipid-mediated gene transfer is a promising approach for gene therapy. However, despite the significant amount of lipoplexes internalized by target cells, transgene expression remains too low. Obstacles to nuclear accumulation of plasmid DNA include: the passage of DNA across the cellular membrane, the dismantling of nucleolipidic particles in the cytoplasm and the nuclear import of plasmid DNA. The purpose of the present study was to evaluate the impact of cell status on cationic lipid-mediated transfer. METHODS: Cells were either growth-arrested (by aphidicolin) or synchronized (by a classical double-thymidine block protocol) and cationic lipid-mediated transfection of these cells was evaluated. For the study of the nuclear import of plasmid DNA, two techniques were developed: microinjection of plasmid DNA into intact cells, and the use of cells permeabilized with digitonin. RESULTS: When CV-1 cells were growth-arrested by aphidicolin, cationic lipid-mediated gene transfer was inhibited. Hela cells were synchronized and incubated with lipoplexes at different times after release of the block. Gene expression was greatly enhanced when cells underwent mitosis. When transfection was performed during the early period after block release, when fewer than 5% of the cells had divided, gene expression was carefully quantified and could be attributed to cells that escaped cell cycle block. However, by direct analysis of nuclear import of GFP-coding plasmid using cytoplasmic microinjection, GFP expression could be detected in a few cells that had not divided. CONCLUSIONS: Cationic lipid-mediated gene transfer efficiency increased when cells underwent mitosis. However, when cells did not divide, gene transfer was not completely abolished. Nuclear import of plasmid was greatly facilitated by a mitotic event. In non-mitotic cells, nuclear envelope crossing by plasmid DNA could be detected but was a very rare event.

Animals↗