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Biomedical subjects

F Jouen

Publications and source records attributed to F Jouen.

At least 19 recordsLinked to original sources
PubMed2006

Autoantibodies, metalloproteinases and bone markers in rheumatoid arthritis patients are unable to predict their responses to infliximab.

OBJECTIVES: To identify biochemical, immunological and bone markers as predictors of rheumatoid arthritis (RA) patients' responses to infliximab. METHODS: A total of 76 patients with active RA (American College of Rheumatology criteria), refractory to disease-modifying anti-rheumatic drugs, including methotrexate, received infliximab (3 mg/kg) infusions at weeks 0, 2, 6, and then every 8 weeks in combination with methotrexate or leflunomide. At week 14, infliximab efficacy was evaluated using disease activity score (DAS)28. A serum sample, collected just before starting infliximab, was tested by ELISA (unless stated otherwise) for the following immunological markers: rheumatoid factor by agglutination and ELISA (IgA, IgG and IgM isotypes); anti-cyclic citrullinated protein; autoantibodies recognizing calpastatin domain I and its 27 C-terminal fragment, glucose-6-phosphate isomerase, alpha-enolase; anti-keratin and anti-perinuclear factor antibodies (immunofluorescence); biochemical markers: C-reactive protein (nephelometry), metalloproteinase-1 and -3, tissue inhibitors of metalloproteinases-1 and -2, antioxidants (vitamins A and E; selenium); bone resorption markers: pyridinoline, deoxypyridinoline, osteoprotegerin, soluble receptor activator of nuclear factor-kappaB ligand, cartilage oligomeric matrix protein. Each parameter's predictive value of the response to infliximab was analysed using Fisher's exact, Mann-Whitney and chi-square tests. Hierarchical clustering was performed with The Institute for Genomic Research (TIGR) multiple experiment viewer software. RESULTS: Good, moderate and non-responder rates were 6.5, 61.8 and 31.5%, respectively. No significant difference was observed between responders and non-responders, regardless of the serum parameters considered. Analysis of dichotomous or continuous variables failed to identify markers predictive of a good or poor response to infliximab. CONCLUSION: The search for soluble markers in RA patients' sera likely to predict response to infliximab because of their involvement in RA pathogenesis seems disappointing. However, because of the limited power to detect smaller differences in biomarkers, the present study is a preliminary exploratory analysis.

Adult↗
PubMed2004

Diagnostic and prognostic values of anti glucose-6-phosphate isomerase antibodies in community-recruited patients with very early arthritis.

The objective of this study was to determine the diagnostic and prognostic values of antiglucose-6-phosphate isomerase (GPI) antibodies in patients with very early arthritis. Anti-GPI antibodies were measured by ELISA using purified GPI from rabbit muscle in: (i) 383 sera from healthy blood donors (n = 120), well-established rheumatoid arthritis (RA) (n = 99) and non-RA differentiated arthritis (NRADA) (n = 164) patients; (ii) 195 sera obtained from community-recruited patients with very early inflammatory arthritis (VErA cohort) that were studied for 1 year and classified as having RA (n = 116), NRADA (n = 41), and undifferentiated arthritis (UA) (n = 38) after the follow-up period. The criterion for severity was the progression of radiographic damage. Prevalence of anti-GPI antibodies was significantly higher in well-established RA patients (45.4%) compared to healthy subjects (2.5%). Anti-GPI antibodies were also present in sera from NRADA: systemic lupus erythematosus 53%, polymyositis 45.4%, adult-onset Still's disease 44%, systemic sclerosis 42.8%, spondylarthropathies 25% and primary Sjögren's syndrome 5.8%. No significant association was found between the presence of anti-GPI antibodies and the 3 diagnostic groups from the VErA cohort. No correlation was observed between anti-GPI and autoantibodies usually associated with RA. Anti-GPI antibodies were not predictive of radiological progression in patients with very early arthritis. Thus, anti-GPI antibodies are not useful for discriminating RA from non-RA rheumatic diseases and do not constitute a predictive factor of structural damage.

Adult↗
PubMed2001

Influence of cholinergic system on motor learning during aging in mice.

Three, 12- and 20-month-old C57Bl6 mice, reared in standard conditions or in an enriched environment, were administered subcutaneously either scopolamine hydrobromide (SIGMA), 0.6 and 1.2 mg kg(-1), or physiological saline 15 min before testing their motor skills (muscular strength, dynamic equilibrium and motor coordination) and motor learning abilities (number of trials needed to reach a learning criterion on a rotorod rotating at 27 revolutions per min). The results demonstrated a lack of correlation between motor skill scores and between motor skill and motor learning scores, suggesting that the rotorod training procedure measures motor learning and not motor skills or is insensitive to changes in motor skills. They also demonstrated that motor skills decreased with age but were insensitive to environmental rearing and to scopolamine. In contrast, the learning scores, which also decreased with age, were very sensitive to scopolamine, particularly in the oldest mice. These results are discussed according to the role of cholinergic system in motor learning during aging.

Aging↗
PubMed2001

Modulation of manual activity by vision in human newborns.

This experiment investigates neonatal intersensory functioning between touch and vision for texture density. The experiment compared manual activity (holding time and hand pressure frequency) recorded on objects in the presence (test period) or absence of visual information (pre-test and post-test periods). Thirty-two babies were assigned to four experimental conditions according to texture density of the objects held and seen during the test period: Objects had either the same (matching conditions) or different (mismatching conditions) texture density information. The results clearly showed that in matching conditions, holding times were systematically increased during the test period. However, hand pressure frequency remained unchanged over the three test periods. In the mismatching conditions, holding times remained unchanged over the three test periods. However, hand pressure frequency systematically changed during the test period according to the texture density of the visual object. These results indicate newborns' capability to compare texture density information across modalities.

Functional Laterality↗
PubMed2000

Potentiation of the effect of an anesthetic, chloral hydrate, by stress and corticosterone: a behavioral study in the mouse.

Many studies have demonstrated that stressors can modify the physiological action of drugs, mainly morphine. The present study investigated the effects of a mild stressor on chloral hydrate (Chl)-induced sedation in mice. For 4 consecutive days, NaCl and Chl-treated mice (300 mg kg(-1)) were stressed (S) either by a 5 min exposure to a brightly lit inescapable open field, or i.p. injected with corticosterone (Cor) (15 mg kg(-1)). Then, their spontaneous motor activity was recorded on an actisystem during 20 min and compared with that of the unstressed (US) NaCl and Chl-treated mice. On day 1 and 4, neither stressor nor i.p. administered Cor had any influence on the spontaneous motor activity of NaCl-treated mice. In Chl-treated mice, the spontaneous motor activity was very low. On day 1, it was similar in S mice, Cor-injected mice, and US mice. On the contrary, on day 4, both stress and Cor enhanced the anesthetic-induced hypoactivity, showing that the magnitude of sedation increased. It can then be stated that stressor, provided it was repeatedly administered, potentiated the sedative action of chloral hydrate and that such a potentiation was probably, but not only, Cor-dependent. Given that stress and Chl both produce dopamine overflow, it can be hypothesized that S, potentiates the sedative action of Chl through a dopaminergic link.

Anesthetics, Intravenous↗
PubMed1999

Role of an enriched environment on the restoration of behavioral deficits in Lurcher mutant mice.

Lurcher mutant mice, characterized by massive degeneration of the cerebellar cortex, and normal littermate controls were reared from birth either in standard conditions or in an enriched environment. The effects of this manipulation on motor functions, landmark water maze learning, exploration, and anxiety were evaluated at 3 months of age. Under standard conditions, Lurcher mutants were impaired in comparison to controls on tests of sensorimotor function and had altered exploratory tendencies. The enriched housing improved the motor coordination of Lurcher mutants and decreased the number of trials before reaching criterion in the landmark water maze. In addition to its effects in Lurcher mutants, enriched rearing also increased some behavioral abilities in normal mice. It is hypothesized that enriched housing altered brain morphology or neurochemistry in both normal and cerebellar-damaged animals.

Animals↗
PubMed1998

Spatial frequency and right hemisphere: an electrophysiological investigation.

The influence of the spatial frequency of visual stimuli on hemispheric asymmetry has been studied with visual evoked potentials (VEP). Nineteen different sinusoidal gratings (19 SF from 1 to 10 cpd) were presented in an ON-OFF mode to five right-handed subjects. The amplitude of the VEPs and the latency of the first positive component (C1) were analyzed. The results show that in the low range of spatial frequencies, the latency and the amplitude of C1 are similar in both hemispheres. At medium to high spatial frequencies, the VEPs on the right hemisphere (RH) present shorter latencies and larger amplitudes than those on the left hemisphere (LH). These results, discussed in relation to the directional differences in the time of callosal interhemispheric transfer, strengthen the idea that the RH is relatively more sensitive than the LH to the spatial component of the visual stimuli.

Brain↗
PubMed1998

Differential roles of cerebellar cortex and deep cerebellar nuclei in learning and retention of a spatial task: studies in intact and cerebellectomized lurcher mutant mice.

Lurcher mutant mice (+/Lc) exhibit a massive loss of neurons in the cerebellar cortex and the inferior olivary nucleus, while deep cerebellar nuclei are essentially intact. To discriminate the relative participation of the cerebellar cortex and deep structures in learning and memory, 3 to 6-month-old +/Lc mice were subjected to a spatial learning task derived from the Morris water escape. They were able to learn to escape as well as their strain-matched controls (+/+). Seven days later, their scores showed that they had memorized the spatial environment but not as accurately as +/+ mice. Cerebellectomy before training did not significantly alter the escape learning capabilities of either group, whereas cerebellectomy performed after learning completely abolished retention in +/+, as well as in +/Lc, mice. These results suggest that the cerebellum, although not necessary for learning a spatial task, plays a crucial role in its retention, and that the storing structure of spatial information differs in +/+ and +/Lc mice.

Analysis of Variance↗
PubMed1995

Phenobarbital in hair and drug monitoring.

Phenobarbital analysis was performed in vertex hair of patients by gas chromatography mass spectrometry (GC/MS). After washing with dichloromethane, about 250 mg were ground to dust in a ball mill. A 50-mg sample was stirred mechanically for 10 min with 3 ml of NH4Cl/HCl buffer (pH 2.0) containing phenobarbital D5. A solid phase extraction was performed (extrelut Merck) and elution was achieved with chloroform/isopropanol/n-heptane (50:17:33; v/v). A full scan (40-240 uma) acquisition was realized by GC/MS with an ion trap (ITD 700 Finnigan) using a DB5-MS chromatographic column. Quantification was achieved by integrating dominants ions (phenobarbital, 204; phenobarbital D5, 209). Compared to serum, hair concentrates phenobarbital during anti-epileptic therapy (average value 36.4 ng/mg, n = 40 vs. 18.7 mg/l, n = 23). A group correlation exists between phenobarbital in hair and phenobarbital in serum, and between phenobarbital in hair and clinic observation in some typical cases. Phenobarbital in hair yields good information over a long period, especially when blood collection has not been made, when clinical disorders are observed on long-term therapeutic observance.

Adult↗
PubMed1993

The effect of linear vection on manual aiming at memorized directions of stationary targets.

Stationary observers were required to aim manually at either a straight-ahead, or a lateral, immobile target (0 degrees and 20 degrees of eccentricity, respectively). First, they aimed at a perceptually present target. Second, they aimed at the memorized direction of the target. Third, they aimed at the memorized direction of the target after a 4 s period of forward sagittal vection. The comparisons of the post-vection versus ante-vection aimings at the memorized direction of the targets reflect an illusory increase in the eccentricity of the lateral target, and no change in the direction of the straight-ahead target. These results objectivate the idea that forward sagittal vection (a particular case of linear vection) corresponds to an illusion of self-displacement, ie an illusory change of body place through space.

Adult↗
PubMed1993

Plasma fluphenazine levels measured by high-performance liquid chromatography in patients treated with depot injections.

Fluphenazine (CAS 69-23-8) concentrations in plasma of schizophrenic patients after oral (fluphenazine hydrochloride, Moditen) or intramuscular (fluphenazine enanthate, Moditen Retard, or fluphenazine decanoate, Modecate) administration of drug were measured by means of high-performance liquid chromatography. The extracted compound was identified by gas chromatography with mass selective detector. Pharmacokinetics of fluphenazine has been studied.

Blood Specimen Collection↗
PubMed1992

Production of a human monoclonal anti-epithelial cell surface antibody derived from a patient with pemphigus vulgaris.

The production of monoclonal autoantibodies derived from individuals with autoimmune diseases constitutes a powerful tool to analyse an autoimmune process at both the antigen and antibody levels. We established a human anti-epithelial cell surface monoclonal antibody by applying hybridoma technology using peripheral blood lymphocytes from a patient with pemphigus vulgaris using a heteromyeloma as the fusion partner. The F12 monoclonal antibody displays four major characteristics: (1) it belongs to the IgM, kappa class; (2) it binds to the cell surface of stratified squamous and simple epithelia; (3) it recognizes an antigenic determinant associated with the desmosomal complex as demonstrated by indirect immunoelectron microscopy; (4) by immunoblotting analysis, it reacts with a 185 kDa polypeptide which was also recognized by a few pemphigus vulgaris sera. Although the F12 monoclonal antibody does not have the immunochemical properties of classical pemphigus vulgaris autoantibodies, several arguments suggest its relevance to the pemphigus vulgaris autoimmune response and, therefore, the heterogeneity of the antigen/antibody systems involved in this autoimmune disorder.

Adolescent↗
PubMed1991

[Verrucous epidermal nevus of the face].

The authors report a case of extensive verrucous epidermal naevus of the face in a 15 year old Senegalese boy. This is the second reported case in Western Africa following the case presented to the French Language African Medical Society in 1984 (B. Ndiaye). The skin lesion in the form of a naevus of variable dimensions is an essential manifestation of the epidermal naevus syndrome described by Solomon, Fretzin and Dewald in 1968. This syndrome consists of a variable but inconstant association of dysembryoplastic abnormalities affecting the central nervous system (epilepsy, mental retardation, hydrocephalus, localized central deficits), the eye (fibrous conjunctival tumours, corneal opacities, colobomas) and the bones (spine, clavicle, pelvis, limb bones). The bones may be affected by malformations or hypoplasia. The epidermal naevus generally has a linear verrucous appearance, but it is not exceptional to find Jadassohn's sebaceous naevus or even localized erythroderma ichthyosiformis. Mucosal lesions, especially oral, well described in 1960 by Brown and Gorlin, correspond to a particular localization of epidermal naevus and must be differentiated histologically from white sponge naevus, which has a fairly similar clinical appearance. This non-hereditary disease must be systematically investigated looking for visceral abnormalities which are very common. Lastly, in terms of therapy, surgery may be justified when the facial lesions are unsightly, extensive or disabling. Various techniques may be applied depending on the extent and the site of these naevi.

Abnormalities, Multiple↗
PubMed1989

A method for the analysis of lithium in liquid droplets using isotopic dilution and SIMS measurements.

An absolute, fairly rapid method for the analysis of lithium in liquid droplets is described. It is based on the isotopic dilution of a 6Li (or 7Li)-enriched lithium salt, and on the measurement of isotopic ratios using Secondary Ion Mass Spectrometry. The sensitivity is well adapted to the analysis of lithium in minute volumes of plasma taken from patients suffering from manic-depressive psychosis.

Isotopes↗
PubMed1985

The influence of body position on perception of orientation in infants.

The present experiment was conducted in order to assess the relative contribution of gravitational and retinal factors in the perception of orientation in infants by studying the effect of body position on the so-called 'oblique effect'. Looking times at vertical, horizontal and oblique patterns were compared in vertical and tilted body positions in 18 infants ranging in age from 3 to 7 months. The results clearly demonstrate the influence of body position on the oblique effect: infants tested in the vertical position showed the classical oblique effect, looking longer at the principal orthogonals than at oblique patterns, while tilted infants spent more time looking at oblique stimuli congruent with body orientation. These results strongly suggest that, in infants, the oblique effect is related to retinal coordinates as determined by body position.

Cues↗