13 research outputs found
Finite element analysis of biomechanical interactions of a subcutaneous suspension suture and human face soft-tissue: a cadaver study
In order to study the local interactions between facial soft-tissues and a
Silhouette Soft suspension suture, a CE marked medical device designed for the
repositioning of soft tissues in the face and the neck, Finite element
simulations were run, in which a model of the suture was embedded in a
three-layer Finite Element structure that accounts for the local mechanical
organization of human facial soft tissues. A 2D axisymmetric model of the local
interactions was designed in ANSYS, in which the geometry of the tissue, the
boundary conditions and the applied loadings were considered to locally mimic
those of human face soft tissue constrained by the suture in facial tissue
repositioning. The Silhouette Soft suture is composed of a knotted thread and
sliding cones that are anchored in the tissue. Hence, simulating these
interactions requires special attention for an accurate modelling of contact
mechanics. As tissue is modelled as a hyper-elastic material, the displacement
of the facial soft tissue changes in a nonlinear way with the intensity of
stress induced by the suture and the number of the cones. Our simulations show
that for a 4-cone suture a displacement of 4.35mm for a 2.0N external loading
and of 7.6mm for 4.0N. Increasing the number of cones led to the decrease in
the equivalent local strain (around 20%) and stress (around 60%) applied to the
tissue. The simulated displacements are in general agreement with experimental
observations
Quantification of two splicing events in the L-type calcium channel alpha-1 subunit of intestinal smooth muscle and other tissues
cDNA fragments encoding a representative region of the L-type calcium channel alpha-1 subunit of rabbit intestine smooth muscle were amplified by polymerase chain reaction (PCR). The nucleotide sequences of these intestine clones shared a high similarity with aorta, lung and heart calcium channels. However, in the extracellular loop between the third and fourth segments of domain IV and in the transmembrane IVS3 segment itself, we observed primary sequence variations corresponding to alternative splicing phenomenons. Since structural differences of L-type calcium channel alpha-1 subunits could result in functional variations, the respective expression frequency of these isoforms was determined in various tissues and species, and in the embryonic A7r5 cell line. The ontogeny of these splicing events was also examined from tissues of different ages. From this quantitative study, carried out by PCR of reverse-transcribed mRNA, it clearly appears that the observed splicing processes in the IVS3-IVS4 region are not only tissue-dependent but also regulated during development
Ultrastructural study of relationships between c-kit immunoreactive interstitial cells and other cellular elements in the human colon
Close relationship between interstitial cells of cajal and sympathetic and substance P nerves in the human colon
Pinaverium bromide prevents spinal Fos expression in acetic acid-induced visceral pain in rats
Rhizobium alamii sp. nov., an exopolysaccharide-producing species isolated from legume and non-legume rhizospheres.
International audienceA group of exopolysaccharide-producing bacteria was isolated from the root environment of Arabidopsis thaliana. The genetic diversity revealed by REP-PCR fingerprinting indicated that the isolates correspond to different strains. 16S rRNA gene sequence analysis showed that the isolates are closely related to the strains Rhizobium sp. YAS34 and USDA 1920, respectively isolated from sunflower roots and Medicago ruthenica nodules. These bacteria belong to the Rhizobium lineage of the Alphaproteobacteria, and the closest known species was Rhizobium sullae. DNA-DNA hybridization experiments and biochemical analysis demonstrated that the nine strains isolated from A. thaliana and Rhizobium strains YAS34 and USDA 1920 constitute a novel species within the genus Rhizobium, for which the name Rhizobium alamii sp. nov. is proposed. The type strain is GBV016(T) (=CFBP 7146(T) =LMG 24466(T))