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A Bonnet

Publications and source records attributed to A Bonnet.

At least 19 recordsLinked to original sources
PubMed2006

Identification of differential gene expression in in vitro FSH treated pig granulosa cells using suppression subtractive hybridization.

FSH, which binds to specific receptors on granulosa cells in mammals, plays a key role in folliculogenesis. Its biological activity involves stimulation of intercellular communication and upregulation of steroidogenesis, but the entire spectrum of the genes regulated by FSH has yet to be fully characterized. In order to find new regulated transcripts, however rare, we have used a Suppression Subtractive Hybridization approach (SSH) on pig granulosa cells in primary culture treated or not with FSH. Two SSH libraries were generated and 76 clones were sequenced after selection by differential screening. Sixty four different sequences were identified, including 3 novel sequences. Experiments demonstrated the presence of 25 regulated transcripts.A gene ontology analysis of these 25 genes revealed (1) catalytic; (2) transport; (3) signal transducer; (4) binding; (5) anti-oxidant and (6) structural activities. These findings may deepen our understanding of FSH's effects. Particularly, they suggest that FSH is involved in the modulation of peroxidase activity and remodelling of chromatin.

Animals↗
PubMed2005

Concentration of remifentanil needed for tracheal intubation with sevoflurane at 1 MAC in adult patients.

BACKGROUND AND OBJECTIVE: Inhalation induction with sevoflurane provides acceptable conditions for tracheal intubation. Opioids significantly decrease the alveolar concentration needed to achieve tracheal intubation. The purpose of this study was to determine the target concentration of remifentanil providing excellent conditions for tracheal intubation with sevoflurane at 1 minimum alveolar concentration without muscle relaxant. METHODS: Twenty-four consecutive patients, aged 18-50 yr, ASA I or II, were studied. Induction of anaesthesia was performed with sevoflurane at age-adjusted minimum alveolar concentration. Remifentanil was simultaneously administered using target-controlled infusion with the Minto model. Target plasma concentration of remifentanil was selected for each patient according to an up-and-down method. RESULTS: The mean target concentration of remifentanil for successful tracheal intubation was 3.3 ng mL(-1) (95% confidence interval: 2.6-3.9 ng mL(-1)). Arterial pressure, heart rate and bispectral index did not increase after tracheal intubation in the group of patients with successful intubation. CONCLUSIONS: Remifentanil at 3.3 ng mL(-1) together with sevoflurane at 1 minimum alveolar concentration provides excellent conditions for tracheal intubation in 50% of patients.

Adolescent↗
PubMed2002

Efficiency of semi-automated fluorescent multiplex PCRs with 11 microsatellite markers for genetic studies of deer populations.

Thirty bovine and eight ovine microsatellite primer pairs were tested on four tropical deer species: Eld's and Swamp deer (highly threatened) and Rusa and Vietnamese Sika deer (economically important). Thirty markers gave an amplified product in all four species (78.9%). The number of polymorphic microsatellite markers varied among the species from 14 in Eld's deer (47%) to 20 in Swamp deer (67%). Among them, 11 microsatellite loci were multiplexed in three polymerase chain reactions (PCRs) and labelled with three different fluorochromes that can be loaded in one gel-lane. To test the efficiency of the multiplex, primary genetic studies (mean number of alleles, expected heterozygosities and Fis values) were carried out on four deer populations. Parentage exclusion probability and probability of identity were computed and discussed on a Swamp deer population. These multiplexes PCRs were also tested on several other deer species and subspecies. The aim of this study is to establish a tool useful for genetic studies of population structure and diversity in four tropical deer species which with few modifications can be applied to other species of the genus Cervus.

Alleles↗
PubMed2001

A novel method to isolate the common fraction of two DNA samples: hybrid specific amplification (HSA).

Hybrid specific amplification (HSA) is a novel simple method elaborated in order to isolate the common fraction of two DNA samples while avoiding the background due to repeated sequences. The method is based on the suppressive PCR principle, associated with a Cot1 pre-hybridization step. In recent work we demonstrated that hyperprolificity observed in Booroola ewes is associated with a mutation in the bone morphogenetic protein receptor IB gene (BMPR-IB). We applied HSA between ovarian cDNA and DNA from four BAC clones containing BMPR-IB in order to test for the presence of other genes expressed in ovary and to isolate additional BMPR-IB exon sequences. Of the 460 clones obtained, none contained repeated sequences. We successfully obtained 37 clones representing the major part of BMPR-IB coding sequence, together with 5'- and 3'-UTR sequences. Here we have successfully applied HSA to a particular tissue, but it should be possible to trap the common fraction of two DNA samples, whatever their nature.

Animals↗
PubMed2001

Characterization of GFP-MAL expression and incorporation in rafts.

During myelin formation, membrane-associated proteins have to be sorted and transported in specified membrane regions such as compact and non-compact myelin membranes. One protein that may be involved in such a process is the Myelin and Lymphocyte protein MAL (VIP17/ MVP17). MAL was identified as a novel myelin membrane component expressed by oligodendrocytes and Schwann cells. Since MAL has been shown to be important in the apical sorting machinery of polarized cells, we have started to investigate the possible functional role of MAL in sorting myelin membrane-associated molecules. In this study, we have generated cDNA constructs with green fluorescent protein (GFP) either at the N- or C-terminus of MAL. Transfection experiments showed that GFP-MAL expression resembles that of normal MAL, whereas the MAL-GFP fusion construct was not properly transported within the cell. Furthermore, we could demonstrate that GFP-MAL is enriched in detergent insoluble glycolipid-enriched microdomains as already seen for untagged MAL. As a prerequisite for the generation of transgenic mice expressing GFP-MAL under the control of its own regulatory elements, we have generated a cDNA construct with an 8-kb MAL promotor fragment fused to GFP-MAL. Transfection experiments of the Oli-neu oligodendrocyte cell line showed that GFP-MAL was expressed, but only in cells, which were stimulated for differentiation with cAMP. In summary, the results confirm that the fusion protein GFP-MAL is incorporated into detergent-insoluble complexes and the 8-kb MAL promotor fragment is sufficient to be activated in oligodendrocytes.

Animals↗
PubMed2001

Cytogenetic comparison between Vietnamese sika deer and cattle: R-banded karyotypes and FISH mapping.

R-banded chromosomes of Vietnamese sika (VS) deer (Cervus nippon pseudaxis, 2N = 66), a threatened subspecies of sika deer endemic to Vietnam, are presented for the first time and were compared with bovine R-banded chromosomes to define a standard karyotype. Nineteen VS deer autosomes (CNP) were identified on the basis of the banding pattern relative to bovine chromosomes (BTA), while hypotheses for the remaining thirteen were proposed from comparisons with the published deer genetic map, BTA 1, 2, 5, 6, 8 and 9 each equivalent to two separate acrocentric CNP chromosomes and BTA 26 and 28 associated in a tandem fusion. To confirm these hypotheses, probes for the twenty-nine Texas nomenclature type I markers specific for each cattle autosome, sixteen other type I and fourteen microsatellite markers were used in FISH experiments on VS deer chromosomes. CNP7 presented the most complex rearrangement as compared with cattle chromosomes. A complete correspondence between VS deer and cattle chromosomes was established and it was extended with a comparison with the human karyotype to transfer human map information to this species of scientific and economic interest. Moreover, this work anchors the deer genetic linkage map to chromosome-specific markers.

Animals↗
PubMed2000

Beta-keto-ester chemistry and ketolides. Synthesis and antibacterial activity of 2-halogeno, 2-methyl and 2,3 enol-ether ketolides.

The effect of 2,3 modifications on the antibacterial activity of ketolides was evaluated by introducing substituents in position 2 and converting the C-1, C-2, C-3 beta-keto-ester into stable 2,3 enol-ether or 2,3 anhydro derivatives. Introduction of a fluorine in C-2 is beneficial with regard to the overall antibacterial spectrum whereas the enol-ether and 2,3 unsaturated compounds, as well as the bulky gem dimethyl or 2-chloro derivatives, are less active particularly against erythromycin resistant strains. A 2-fluoro ketolide derivative demonstrates good antibacterial activity and in vivo efficacy against multi-resistant Streptococcus pneumoniae. Compared to azithromycin against Haemophilus influenzae, this compound is equivalent in vitro and slightly more active in vivo. These results demonstrate that within the ketolide class, to retain good antibacterial activity, position 2 needs to remain tetrahedral and tolerates only very small substituents such as fluorine.

Animals↗
PubMed1999

Facial reflex myoclonus induced by language: a neuropsychological and neurophysiological study.

We studied a 53 year old right-handed patient who presented isolated myoclonus of right facial muscles induced exclusively by language. Twitching significantly hindered speaking and reading performance. MRI and CT-scan revealed no brain lesion. Conventional EEG showed a few spike-waves predominantly in the left hemisphere. Spike-waves increased during drowsiness. An EEG-EMG polygraphic study was performed during stimulation tests which included linguistic tasks and non-verbal/non-linguistic tests. Myoclonus was triggered by speaking and writing but not by non-linguistic tasks. The severity of myoclonus was dependent on the complexity of the language task. Back-averaging of right facial EMG bursts failed to show a reliable EEG-EMG correlation. However, the facial reflex myoclonus might have originated from the left rolandicopercular cortex, as it was triggered by complex language activities. Findings in this case are compared with those reported for other forms of reflex seizure and myoclonus.

Electroencephalography↗
PubMed1999

beta-thymosin is required for axonal tract formation in developing zebrafish brain.

beta-Thymosins are polypeptides that bind monomeric actin and thereby function as actin buffers in many cells. We show that during zebrafish development, &bgr;-thymosin expression is tightly correlated with neuronal growth and differentiation. It is transiently expressed in a subset of axon-extending neurons, essentially primary neurons that extend long axons, glia and muscle. Non-neuronal expression in the brain is restricted to a subset of glia surrounding newly forming axonal tracts. Skeletal muscle cells in somites, jaw and fin express beta-thymosin during differentiation, coinciding with the time of innervation. Injection of beta-thymosin antisense RNA into zebrafish embryos results in brain defects and impairment of the development of beta-thymosin-associated axon tracts. Furthermore, irregularities in somite formation can be seen in a subset of embryos. Compared to wild-type, antisense-injected embryos show slightly weaker and more diffuse engrailed staining at the midbrain-hindbrain boundary and a strong reduction of Isl-1 labeling in Rohon Beard and trigeminal neurons. The decreased expression is not based on a loss of neurons indicating that beta-thymosin may be involved in the maintenance of the expression of molecules necessary for neuronal differentiation. Taken together, our results strongly indicate that beta-thymosin is an important regulator of development.

Amino Acid Sequence↗
PubMed1998

[Areactive unilateral mydriasis after diagnostic celioscopy under general anesthesia].

A unilateral areactive mydriasis occurred in a 49-year-old ASA I woman after a coelioscopic procedure while anaesthesia was maintained for an associated procedure. The various causes of brain stem damage were considered. The inability to perform a complete neurologic assessment resulted in the indication of a cerebral computerised tomography (CT) scan. The diagnosis of Adie's tonic pupil was made a posteriori, taking into consideration: 1) complete recovery without neurologic deficit; 2) unremarkable CT scan; 3) previous transient episodes of unilateral areactive mydriasis.

Anesthesia, General↗
PubMed1998

Characterization of FSH-regulated genes isolated by mRNA differential display from pig ovarian granulosa cells.

The present authors have isolated FSH-regulated genes from primary granulosa cell cultures with or without Follicle Stimulating Hormone (FSH) treatment using mRNA differential display. mRNA differential display consists of amplification of partial sequences of cDNAs (150-400 bp) corresponding to 3' ends of cellular messenger RNAs, and thus, generates 3' expressed sequence tags (3' ESTs). Five thousand cDNA bands were examined, among which the present authors have isolated and sequenced 16 different FSH-regulated products. These sequences were compared with those available in databases. Three of the sequences showed similarity to identified genes from other species (bovine NADH dehydrogenase subunit 4, Xenopus chromosome sequence-associated polypeptide E and transformation-sensitive protein IEF SSP) and four others with human ESTs. Regulation of the corresponding genes has been checked by RT-PCR since most of these are expressed at a low level. FSH-regulation was confirmed for 12 mRNAs (four down- and eight up-regulated). The present authors have also mapped 12 of these ESTs on porcine chromosomes regions using a somatic cell hybrid panel.

Animals↗
PubMed1997

A first catalog of genes involved in pig ovarian follicular differentiation.

As a first step toward the characterization of genetic expression in pig ovaries, we have selected 238 clones by differential hybridization from a pig granulosa cell cDNA library, using probes prepared from RNA extracted from either untreated or FSH-treated cells and, in order to generate expressed sequence tags (ESTs), we have performed 3' and 5' single-pass sequencing of these clones. Sequences of the 3' end of the 167 clones that produced informative sequence data were first compared with each other, revealing a redundancy level of 21%. Sequences from the 136 unique clones were analyzed for similarities with sequence data included in Genbank and EMBL databases. Among these unique clones, 54 (40%) matched significantly with sequences from either Genbank of EMBL: 4 with known genes in pig, 35 matched with previously reported human genes, and 15 with other mammalian genes. Eighty-two clones (60%) showed no significant match with any gene or DNA sequence in the Genbank and EMBL databases and thus may represent new pig transcripts.

Animals↗
PubMed1995

Protein kinase C inhibition of in vitro FSH-induced differentiation in pig granulosa cells.

In granulosa cells, growth factor IGF I plays a major role in both growth and differentiation, acting through an autocrine/paracrine mechanism, and its production is regulated by FSH, via cyclic AMP (cAMP). As protein kinase C is also involved in granulosa cell function, we investigated the possibility that its activation could balance the positive effects of FSH. Using pig granulosa cells cultured in vitro, we studied the effects of protein kinase C activation by tetradecanoylphorbol acetate (TPA) on IGF I mRNA level. We also checked morphological modifications, cAMP production and steroidogenesis at the P450 side chain cleavage mRNA and progesterone levels. Our data demonstrate that protein kinase C activation antagonizes the in vitro FSH-induced differentiation, particularly morphological modifications and accumulation of IGF I mRNA. These inhibitory effects on FSH responses suggest that there could be a balance between protein kinase A and protein kinase C pathways in regulating differentiation in pig granulosa cells.

Animals↗
PubMed1993

A fluorometric deoxyribonucleic acid assay for tridimensional lattice cultures of fibroblasts.

A fast and sensitive in situ assay of deoxyribonucleic acid in miniaturized lattice cultures of fibroblasts is described. Tridimensional collagen and fibrin lattices prepared in 24-well plates were seeded with 50,000 to 200,000 cells. Cultures were fixed with formaldehyde, rinced with isopropanol, and dried. DNA assay was performed directly in the wells by addition of 3,5-diaminobenzoic acid (DABA) reagent. A calibration curve was prepared with calf thymus DNA. Fluorescence of DNA-DABA was evaluated after 45 min incubation (excitation wavelength 420 nm, emission wavelength 490 nm). The method showed linear results from 0.5 to 10 micrograms DNA and proved sensitive for low cell numbers (50,000 per dish). DNA assay in monolayers and in different types of lattices showed that comparable results were obtained in the different models without interference of the extracellular matrix. This technique is regarded as a costless and efficient tool for evaluating the number of cells in lattices in basal conditions or under pharmacological stimulation.

Aminobenzoates↗
PubMed1993

[Cesarean section, mitral valve disease and pulmonary hypertension. Implications of hemodynamic monitoring on anesthetic management].

We present the case of a 25-year-old woman with mitral valve disease and severe pulmonary hypertension scheduled for Caesarean section under general anaesthesia. General anaesthesia for such cardiac patients requires usually high doses of fentanyl prior to intubation, which favours maternal inhalation and neonatal ventilatory depression. Invasive haemodynamic monitoring allowed a rapid sequence induction, with an optimal drug titration and an early recovery.

Adult↗
PubMed1992

Gonadotropins induce accumulation of insulin-like growth factor I mRNA in pig granulosa cells in vitro.

Pig granulosa cells have been shown to synthesize insulin-like growth factor (IGF) I peptide in vitro, and this expression is regulated by gonadotropins via the cAMP pathway. By hybridizing an IGF I cDNA probe with total RNA isolated from pig granulosa cells cultured in vitro, we show that these cells contain two IGF I transcripts of about 0.9 kb and 9 kb in size. Treatment of the cells with gonadotropins (follicle-stimulating hormone, luteinizing hormone) or cAMP agonists (dibutyryl-cAMP, forskolin) induces an accumulation of the transcripts which can be abolished by transcriptional inhibitors, but not by translational inhibitors. We thus provide new evidence that pig granulosa cells are a site of IGF I synthesis, and we conclude that (1) gonadotropins increase IGF I mRNA levels; (2) the accumulation of IGF I mRNA results from an increased transcription; (3) the stimulation of IGF I gene transcription does not require ongoing protein synthesis; (4) these effects of follicle-stimulating hormone can be mimicked by cAMP agonists.

Animals↗