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Biomedical subjects

P Fournier

Publications and source records attributed to P Fournier.

At least 55 records · Page 3Linked to original sources
PubMed1998

[Emergency EEG and brain injuries].

The aim of this study is to review indications for emergency EEG in case of brain trauma. The authors emphasize the indication of emergency EEG for the diagnosis of either cerebral death or early post traumatic seizures, and for the monitoring of intensive neurological treatments. Emergency EEG and diagnosis of cerebral death has been reviewed in another issue of this journal. Diagnosis of early post-traumatic seizures may be difficult in case of cranial trauma in either the presence or the absence of coma. Emergency EEG help guide the diagnosis of electrical signs of seizures, thus indicating that treatment with antiepileptic drugs is advisable. Severe post-traumatic coma requires barbiturate impregnation and moderate hypothermia. In this last case, emergency EEG is essential for the monitoring of pharmacological treatments. The authors conclude that continuous EEG monitoring could in the future substitute for standard EEG recorded in emergency.

Brain Death↗
PubMed1998

Processing of the DRB1*1103-restricted measles virus nucleoprotein determinant 185-199 in the endosomal compartment.

MHC class II molecules present to CD4+ T cells protein fragments which mostly derive from the extracellular and from the endosomal compartments. Determinants of cytosolic proteins are, however, also displayed by MHC class II molecules following pathways which are still not yet fully characterized. Here we describe the isolation of DRB1*1103-restricted T cell clones specific for the measles virus (MV) nucleoprotein peptide 185-199 (N185). Experiments were then conducted to delineate how this determinant is assembled with DR molecules. In vitro binding analyses indicated that complexes between the N185 peptide and DRB1*1103 protein are optimally constituted at pH 4-4.5. In cellular experiments it was observed that chloroquine, leupeptin and emetine, which are classical inhibitors of presentation of MHC class II-restricted antigens, when added during infection of B cells with MV, prevent presentation of the N185 determinant. In addition, it was found that the N185 determinant is efficiently presented when the nucleoprotein is exogenously provided to B cells, either by blocking MV fusion with the peptide FFG or by the use of purified nucleoprotein. In contrast, it was observed that nucleoprotein recombinant vaccinia virus (vv-N)-infected B cells weakly stimulated N185-specific T cells, indicating that the restricted localization of the nucleoprotein in the cytosol resulted in a poor presentation of the N185 determinant. Taken together, these findings suggest that it is prior to delivery of the nucleoprotein into the cytosol that the N185 determinant is efficiently assembled with newly synthesized DR molecules in the acidic environment of the endosomal compartment.

Amino Acid Sequence↗
PubMed1998

Measuring lay people's perceptions of the quality of primary health care services in developing countries. Validation of a 20-item scale.

INTRODUCTION: Methodologies that have been developed and validated in accordance with accepted scientific standards are needed to monitor and assess the quality of primary health care in developing countries. OBJECTIVE: To present the results of reliability and validity testing of a new instrument of measurement intended to document the user's opinion on the quality of primary health care services. METHODS: The 20-item scale includes three subscales related to health care delivery personnel and facilities. There were 241 people in one city and two villages in Upper Guinea who responded to the questionnaire. An item analysis preceded the test of psychometric properties of the three subscales and of the total score. Reliability was estimated by analyses of internal consistency and the Cronbach's alpha coefficient. A variety of statistical procedures were used to test factorial validity, trait validity (convergent and discriminant) and nomological validity. RESULTS: The reliability of the subscales ranged from 0.71 to 0.88. The validity analyses supported the initial dimensionality and suggested good construct validity. CONCLUSION: Results confirm the value of the use of the scale developed and highlight the need to take into account the diversity of how quality is perceived by lay people in developing countries. It is suggested that the process of formalization of this type of measurement scale be pursued.

Adult↗
PubMed1998

Hematology and serum biochemistry values of free-ranging red howler monkeys (Alouatta seniculus) from French Guiana.

One hundred twenty-two wild red howler monkeys (Alouatta seniculus) were translocated during flooding of the forest at a hydroelectric dam site in French Guiana. Blood samples from 103 animals were evaluated for 13 hematologic and/or 22 serum chemistry parameters. Significant age-specific variation was found for white blood cell (WBC), lymphocyte, and platelet counts and for alkaline phosphatase values. Adult males and females had significant differences in red blood cell count, packed cell volume, and hemoglobin, creatinine, cholesterol, and calcium values. In juveniles, amylase and cholesterol levels were significantly lower in males than in females. Significant differences associated with reproductive status were also observed; i.e., lower cholesterol level in pregnant females and higher packed cell volume in lactating females. Chronic stress due to habitat disappearance may have been responsible for significant differences between thin animals and those in good condition. Thin animals had lower WBC, eosinophil, basophil, and monocyte counts and higher platelet counts. Capture stress was probably responsible for high and variable levels of creatine kinase, aspartate aminotransferase, and lactate dehydrogenase.

Age Factors↗
PubMed1998

Immobilization of wild kinkajous (Potos flavus) with medetomidine-ketamine and reversal by atipamezole.

As part of a wildlife rescue during the filling of a lake created by a hydroelectric dam (Petit Saut, French Guiana), 10 wild kinkajous (Potos flavus) were immobilized with medetomidine and ketamine for clinical examination and collection of biological samples. A mean (+/-SD) i.m. dose of 0.11+/-0.01 mg/kg medetomidine and 5.5+/-0.6 mg/kg ketamine rapidly induced complete immobilization (3.0+/-0.9 min) with good muscle relaxation and loss of corneal and pedal withdrawal reflexes. The duration and the quality of the anesthesia allowed procedures including minor surgery. Rectal temperature, heart and respiration rates, and relative oxyhemoglobin saturation (SpO2) were monitored at 5 min, 15 min, and 30 min after the medetomidine ketamine injection. Rectal temperature and heart rate significantly decreased during this time (P < 0.05). Low values of SpO2 (<90%) were recorded shortly after the injection. Hypoxemia partially resolved with time, confirmed by an increase in most SpO2 values. Atipamezole given i.m. at 5 mg/mg of medetomidine reversed the effects of the medetomidine in kinkajous. No adverse effects were observed during recovery. In group I, the antagonist was injected at 40.6+/-3.9 min. In group II, the animals showed signs of spontaneous recovery 37.9+/-6.9 min before antagonist injection at 52.2+/-6.1 min. Time from antagonist injection to ambulatory state was significantly shorter (P < 0.05) in group II (2.8+/-1.1 min) than in group I (6.9+/-1.2 min).

Adrenergic alpha-Agonists↗
PubMed1998

[Prevention priorities in mental health in Geneva: a study using the Delphi technic].

A Delphi technique was used to determine priorities for mental health prevention in Geneva. The study comprised two rounds of postal questionnaires targeted at 58 participants concerned and/or interested by mental health through their association or their work. From the responses given in the first round mental health problems were listed, essentially health problems (65%) and service problems (11%) and less frequently resources problems (< 1%). Consensus produced in the second round indicated that 3 problems were priorities for the development of preventive measures: depression, alcohol abuse, maltraitance and sexual abuse. Using the Delphi technique, a qualitative method corresponding to a subjective consensus issued from a group of experts, priorities for mental health prevention were identified in Geneva, in 1995.

Adolescent↗
PubMed1997

Genomic organization of the yeast Yarrowia lipolytica.

We produced electrophoretic karyotypes of the reference strain E150 and of seven other isolates from different geographical origins to study the genomic organization of the dimorphic yeast Yarrowia lipolytica. These karyotypes differed in the number and size of the chromosomal bands. The karyotype of the reference stain E150 consisted of five bands of between 2.6 and 4.9 Mb in size. This strain contained at least five rDNA clusters, from 190 to 620 kb in size, which were scattered over most of the chromosomes. The assignment of 43 markers, including rRNA genes and three centromeres, to the E150 bands defined five linkage groups. Hybridization to the karyotypes of other isolates with pools of markers of each linkage group showed that linkage groups I, II, IV and V were conserved in the strains tested whereas group III was not and was split between at least two chromosomes in most strains. Use of a meganuclease I-SceI site targeted to one locus of E150 linkage group III showed that two chromosomes actually comigrated in band III of this strain. Our results are compatible with six chromosomes defining the haploid complement of strains of Y. lipolytica and that, despite an unprecedented chromosome length polymorphism, the overall structure of the genome is conserved in different isolates.

Ascomycota↗
PubMed1997

Antibodies to a new linear site at the topographical or functional interface between the haemagglutinin and fusion proteins protect against measles encephalitis.

The haemagglutinin protein (H) of measles virus (MV) binds to susceptible cells and collaborates with the fusion protein (F) to mediate fusion of the virus with the cell membrane. Binding and fusion activity of the virus can be monitored by haemagglutination and haemolysis, respectively, of monkey erythrocytes. Most monoclonal antibodies (MAbs) with haemolysis inhibiting activity (HLI+) are either MV-F specific and do not inhibit haemagglutination (HI-), or they bind to MV-H and are HI+ by interfering with virus binding. We describe here a small panel of H-specific MAbs (BH47, BH59, BH103, BH129) which bind to a new linear neutralizing epitope, H244-250 (SELSQLS; NE domain), and which prevent virus-cell fusion (HLI+) but not virus binding (HI-). These antibodies also protect against MV encephalitis in an animal model. They do not compete with an HLI+/HI+ antibody (BH216) which binds to the haemagglutinin noose epitope (HNE). The antibodies described here and the HNE-specific antibodies are functionally distinct and define two topographically non-overlapping interfaces, supposedly with a bias towards the host cell MV-receptor and the fusion protein respectively. The proximity of the CD46 downregulating amino acid Arg-243 may suggest a functional link between the domain described here and the CD46 binding domain. This new protective linear site is also of potential interest for the design of a subunit-based vaccine.

Animals↗
PubMed1997

Muscle phosphocreatine repletion following single and repeated short sprint efforts.

Phosphocreatine (PCr) repletion following either single (1x6 s, n=7) or repeated (5x6 s, departing every 30 s, n=8) maximal short sprint cycling efforts was measured in separate groups of trained subjects. Muscle biopsies (vastus lateralis) were taken pre-exercise before warming up, and then at 10 s, 30 s and 3 min post-exercise. After the 1 x 6 s sprint PCr concentration was respectively, 55% (10 s; P<0.01), 69% (30 s; P<0.01) and 90% (3 min; NS) of the pre-exercise value (mean+/-SD) (81.1+/-7.4 mmol x kg(-1) DM), whereas after the 5x6 s sprints, PCr concentration was, respectively, 27% (10 s; P<0.01), 45% (30 s; P<0.01) and 84% (3 min; P<0.01) of the pre-exercise value (77.1+/-4.9 mmol x kg(-1) DM). PCr concentration was correlated with muscle lactate at 30 s (r=-0.82; P<0.05) and 3 min of recovery (r=-0.94; P<0.01) for the 1x6 s sprint, but not for the 5x6 s sprints. The extent of PCr repletion was significantly greater after the 5x6 s sprints than the 1x6 s sprint between both 10 s and 30 s and 30 s and 3 min, despite lower PCr levels at 10 s, 30 s and 3 min following the 5x6 s sprints. Full repletion of PCr is likely to take longer after repeated sprints than single short sprints because of a greater degree of PCr depletion, such that replenishment must commence from lower PCr levels rather than because of slower rates of repletion.

Adult↗
PubMed1997

An origin of replication and a centromere are both needed to establish a replicative plasmid in the yeast Yarrowia lipolytica.

Two DNA fragments displaying ARS activity on plasmids in the yeast Yarrowia lipolytica have previously been cloned and shown to harbor centromeric sequences (P. Fournier, A. Abbas, M. Chasles, B. Kudla, D. M. Ogrydziak, D. Yaver, J.-W. Xuan, A. Peito, A.-M. Ribet, C. Feynerol, F. He, and C. Gaillardin, Proc. Natl. Acad. Sci. USA 90:4912-4916, 1993; and P. Fournier, L. Guyaneux, M. Chasles, and C. Gaillardin, Yeast 7:25-36, 1991). We have used the integration properties of centromeric sequences to show that all Y. lipolytica ARS elements so far isolated are composed of both a replication origin and a centromere. The sequence and the distance between the origin and centromere do not seem to play a critical role, and many origins can function in association with one given centromere. A centromeric plasmid can therefore be used to clone putative chromosomal origins coming from several genomic locations, which confer the replicative property on the plasmid. The DNA sequences responsible for initiation in plasmids are short (several hundred base pairs) stretches which map close to or at replication initiation sites in the chromosome. Their chromosomal deletion abolishes initiation, but changing their chromosomal environment does not.

Base Sequence↗
PubMed1997

Immobilization of wild collared anteaters with ketamine- and xylazine-hydrochloride.

Collared anteaters (Tamandua tetradactyla) were immobilized for clinical procedures as part of a wildlife rescue during the filling of a hydroelectric dam (Petit Saut, French Guiana) from March 1994 to March 1995. Two doses of ketamine hydrochloride (KH) (group I mean +/- SD = 11.2 +/- 1.4 mg/kg, group II = 19.7 +/- 1.3 mg/kg) in combination with xylazine hydrochloride (XH) (1.0 +/- 0.1 mg/kg) were evaluated in seven and 10 collared anteaters, respectively. Induction time did not differ between the two groups. Immobilization time was significantly longer in group II than in group I (48.3 +/- 15.8 min and 35.0 +/- 9.5 min, respectively), without lengthening the recovery process. Adverse effects were not observed. The degree of anesthesia and the muscle relaxation were better in group II than in group I. Rectal temperature decreased in both groups and was significantly higher in group II than in group I. Heart rate was significantly higher in group II than in group I at 5 min post-injection and decreased in group II. No effects on respiratory rate were observed. We recommend the 20 mg/kg KH -1 mg/kg XH combination, especially for manipulations longer than 30 to 40 min and for minor surgery procedures.

Anesthesia↗
PubMed1996

Excitation Gap in the Normal State of Underdoped Bi2Sr2CaCu2O8+delta

Angle-resolved photoemission experiments reveal evidence of an energy gap in the normal state excitation spectrum of the cuprate superconductor Bi2Sr2CaCu2O8+delta. This gap exists only in underdoped samples and closes around the doping level at which the superconducting transition temperature Tc is a maximum. The momentum dependence and magnitude of the gap closely resemble those of the dx2-y2 gap observed in the superconducting state. This observation is consistent with results from several other experimental techniques, which also indicate the presence of a gap in the normal state. Some possible theoretical explanations for this effect are reviewed.

Journal Article↗