PubMed Health⌕ Search

Biomedical subjects

V Brun

Publications and source records attributed to V Brun.

11 recordsLinked to original sources
PubMed2002

[How to investigate a patient with exophthalmos?].

Exophthalmos is the main symptom revealing orbital masses. This sign needs to be imaged mainly by MRI and/or CT. As Graves disease is the main etiology of exophthalmos, CT scan should be performed as the initial imaging modality. Indications for US and Doppler are mostly limited to the study of ocular masses, and eventually may help the characterization of extra-ocular lesions. In all cases, imaging is useful to characterize: the precise location of the lesion which can be the intra-conal space (including muscles), the extra-conal space (associated or not to an extra-orbital lesion), or the eyeball; the features of the lesion (density, signal, enhancement.). These findings are used to generate a differential diagnosis. Imaging is also useful to precise the extension of the mass, and in some cases to select the appropriate surgical approach, and for follow-up.

Diagnosis, Differential↗
PubMed2001

Nuclear methods to characterize biomaterials.

Techniques using X-rays are often used to study biomaterials fields. However, when one is interested by quantitative and very sensitive measurements, it is valuable to develop nuclear instruments and methods, in addition and complement with others. Fast neutron activation is appropriate for non-destructive analysis. Thermal neutron activation can evaluate trace elements as a reference. Proton-induced X-rays emission is applied to cartography of heavy elements. If necessary, proton-induced gamma-rays emission and charged particles scattering are suitable for evaluation and cartography of light elements. Radioactivated nuclei and labelled molecules can tag element transfers and biofunctionality. In our work, these methods are related to biomaterials field.

Animals↗
PubMed1999

Determination of metallic ion transfer from an implanted prosthesis by the PIXE method.

Prostheses can release some metallic elements to the surrounding tissues, particularly when they are not covered with a biomaterial layer and when an unsealing process happens. We try to measure major and trace elements in these tissues with an experimentally sensitive method. Proton-induced X-ray emission is used to detect about 10 elements in tissue. Tissues are calcinated and deposited in a thin layer before irradiation. Results are obtained in a standard and samples from three patients. We observe contamination by Ti, Cr, Ni, and Zn in the tissues. Correlations are to be studied between these atomic transfers and prosthesis in the patient.

Hip Prosthesis↗
PubMed1999

Study of implanted biomaterial functionality by diphosphonate molecules labeled with radioactive 99mTc.

An implanted biomaterial can be transformed into young bone after some months, but it has not necessary reached full biofunctionality. Mineral concentration kinetics and crystal-structure studies, still being carried out in our group, are completed here by biofunctionality determinations. A natural coral is implanted in vivo at the cortical level of the femoral diaphyoff++ in rabbits. Diphosphonates molecules labeled with radioactive 99mTc are then injected in rabbits and the fixation of the radioactivity is analyzed in several sites for 8 mo after the implantation. Nuclear instruments and methods are used for the measurements. Four successive cycles of osseous remodeling are determined before reaching a biofunctional phase.

Animals↗
PubMed1997

Influence of sports discipline on shoulder rotator cuff balance.

Isokinetic shoulder rotational strength was evaluated in four groups of subjects as follows: 12 nonathletes, 12 runners, 15 tennis players, and 12 baseball players for a total of 51 subjects. The tests were performed in the seated 45 degrees abducted test position in the scapular plane at 60, 180, and 300 degrees.s-1 for both shoulders. Peak torque and mean power values were gathered, and from these values the internal/external rotation ratios were calculated. Intergroup comparison showed a progression of the ratio related to the sports discipline. The nonathletes and runners had ratios close to those reported for nonathletes (1.3 to 1.5). The tennis players had ratios close to 1.5, whereas the baseball players had ratios from 1.6 to 2.2. The comparison between dominant and nondominant side showed no significant differences in the tennis players and higher values for the dominant side in the nonathletes and runners under certain conditions (180 degrees.s-1 for the nonathletes and 300 degrees.s-1 for the runners). Regarding the baseball players, the ratio was systematically higher for the dominant side. These results raise questions about the influence of sports discipline on the internal/external rotator muscle ratio and indicate the need to establish normative values based on the characteristics of the population under study.

Adult↗
PubMed1997

Salience of central figure in the Ebbinghaus illusion: the Oreo cookie effect.

The Ebbinghaus illusion was used to study size estimation as influenced by salient features of the central figure. Two groups of fourth graders, 9 boys and 11 girls, and two groups of seventh graders, 9 boys and 9 girls, judged the size of two central figures (an Oreo cookie or a black cardboard disc) with small and large black cardboard disc inducers. Responding showed the Oreo cookie was consistently perceived as larger than the cardboard disc when surrounded by the large inducing figures. The results are discussed in terms of an interaction between the geometric properties and salience of the central figure with the surrounds. This Oreo effect is not predicted by a strict version of the token-value hypothesis and differs from explanations based on contrast and conceptual similarity.

Age Factors↗
PubMed1995

[Can outcome of varicella pneumonia be predicted in a non-immunosuppressed patient?].

Varicella rarely occurs in the adult but can cause multi-organ complications. The most frequent (15 to 30% involve varicella pneumonia of unpredictable outcome. In the healthy adult, outcome can be favourable in 5 days or inversely lead to respiratory distress and death in 10 to 20% of the cases. An analysis of the published cases does not reveal any factor predicting unfavourable outcome. A register of varicella pneumonia would help identify potential predictive factors.

Adult↗
PubMed1989

High affinity acceptor sites in guinea pig brain for [3H]52770 RP, a PAF antagonist.

[3H]52770 RP, a PAF antagonist, was found to bind with high affinity and in a reversible manner on specific and saturable binding sites in guinea pig cortical membranes. Scatchard analysis revealed the presence of one class of binding sites with an equilibrium dissociation constant of 0.38 nM and a Bmax of 1190 fmol/mg protein. However, these binding sites did not correspond to the PAF receptors described with this ligand in platelet plasma membranes; indeed, PAF and its analogs were unable to displace [3H]52770 RP binding in guinea pig brain. Therefore, one may conclude that [3H]52770 RP in guinea pig brain labels acceptor or recognition sites, rather than true receptor sites.

Animals↗