University of Rouen

About: University of Rouen is a education organization based out in Rouen, France. It is known for research contribution in the topics: Population & Receptor. The organization has 7299 authors who have published 13209 publications receiving 313477 citations.

Poststroke dysphagia rehabilitation by repetitive transcranial magnetic stimulation: a noncontrolled pilot study.

Abstract: Poststroke dysphagia is frequent and significantly increases patient mortality. In two thirds of cases there is a spontaneous improvement in a few weeks, but in the other third, oropharyngeal dysphagia persists. Repetitive transcranial magnetic stimulation (rTMS) is known to excite or inhibit cortical neurons, depending on stimulation frequency. The aim of this noncontrolled pilot study was to assess the feasibility and the effects of 1-Hz rTMS, known to have an inhibitory effect, on poststroke dysphagia. Seven patients (3 females, age = 65 ± 10 years), with poststroke dysphagia due to hemispheric or subhemispheric stroke more than 6 months earlier (56 ± 50 months) diagnosed by videofluoroscopy, participated in the study. rTMS at 1 Hz was applied for 20 min per day every day for 5 days to the healthy hemisphere to decrease transcallosal inhibition. The evaluation was performed using the dysphagia handicap index and videofluoroscopy. The dysphagia handicap index demonstrated that the patients had mild oropharyngeal dysphagia. Initially, the score was 43 ± 9 of a possible 120 which decreased to 30 ± 7 (p < 0.05) after rTMS. After rTMS, there was an improvement of swallowing coordination, with a decrease in swallow reaction time for liquids (p = 0.0506) and paste (p < 0.01), although oral transit time, pharyngeal transit time, and laryngeal closure duration were not modified. Aspiration score significantly decreased for liquids (p < 0.05) and residue score decreased for paste (p < 0.05). This pilot study demonstrated that rTMS is feasible in poststroke dysphagia and improves swallowing coordination. Our results now need to be confirmed by a randomized controlled study with a larger patient population.

Melanocortin‐3 Receptor mRNA Expression in Pro‐Opiomelanocortin Neurones of the Rat Arcuate Nucleus

Abstract: The melanocortins alpha- and gamma-melanocyte-stimulating hormones (alpha- and gamma-MSH) derive from the pro-opiomelanocortin (POMC) precursor. Melanocortins exert a wide range of biological activities in the brain through activation of at least three distinct melanocortin receptor (MC-R) subtypes. In order to determine whether POMC neurones can modulate their own activity, we looked for the possible expression of the MC3-R gene in POMC-positive cell bodies in the rat hypothalamus. In situ hybridization experiments revealed that the density of MC3-R mRNA is particularly high in the arcuate nucleus which contains the main population of POMC neurones in the brain. The occurrence of MC3-R mRNA in POMC-positive cell bodies was demonstrated using a double-labelling in situ hybridization technique. The proportion of POMC neurones expressing MC3-R mRNA was significantly higher in the most rostral (43.5%) than in the most posterior part of the arcuate nucleus (8.2%). These results indicate that melanocortins likely exert a direct regulatory feedback on POMC neurones through activation of MC3-R receptors. Our data also suggest that MC3-R may be involved in the neuroendocrine responses induced by centrally administered melanocortins.

Effects of the preferential segregation of droplets on evaporation and turbulent mixing

Abstract: Droplet segregation in isotropic homogeneous turbulence is analysed using a spectral direct numerical simulation solver to describe the evolution of the turbulent carrier phase, whose characteristic properties remain statistically stationary due to a semi-deterministic forcing scheme. Lagrangian dilute spray modelling is employed to describe the discrete-phase evolution. The liquid density is distributed on an Eulerian mesh to analyse the evolution of the spray and its spatial distribution. This gives results in accordance with classical methods for droplet segregation. It also allows a deeper analysis of the spray evolution. In particular, droplet segregation and vapour mass fraction may be analysed jointly. First, droplet segregation phenomena are studied through the analysis of the formation and the geometry of the droplet clusters. Then, the effects of segregation on spray evaporation are investigated from both the dispersed and carrier phase points of view. At equilibrium, droplet dynamics leads to different segregation levels that are associated with characteristic Stokes numbers. It appears that the evaporation process evolves in three different stages in time: single-droplet mode in the early stage, cluster mode in the intermediate stage and a gaseous mode in the late stage. Segregation levels strongly affect the evolution of the mean vapour mixture fraction during the second stage, while the corresponding standard deviation is affected for longer, up to the third stage in our simulations. However, from the evolution of the integral scale and the shape of the energy spectrum, it appears that turbulent mixing eliminates the segregation effects, apart from the first evaporation stage when the droplet segregation determines the vapour distribution.