University of Geneva

About: University of Geneva is a education organization based out in Geneva, Switzerland. It is known for research contribution in the topics: Population & Galaxy. The organization has 26887 authors who have published 65265 publications receiving 2931373 citations. The organization is also known as: Geneva University & Universite de Geneve.

Mutations in the channel domain alter desensitization of a neuronal nicotinic receptor.

Abstract: A variety of ligand-gated ion channels undergo a fast activation process after the rapid application of agonist and also a slower transition towards desensitized or inactivated closed channel states when exposure to agonist is prolonged. Desensitization involves at least two distinct closed states in the acetylcholine receptor, each with an affinity for agonists higher than those of the resting or active conformations. Here we investigate how structural elements could be involved in the desensitization of the acetylcholine-gated ion channel from the chick brain alpha-bungarotoxin sensitive homo-oligomeric alpha 7 receptor, using site-directed mutagenesis and expression in Xenopus oocytes. Mutations of the highly conserved leucine 247 residue from the uncharged MII segment of alpha 7 suppress inhibition by the open-channel blocker QX-222, indicating that this residue, like others from MII, faces the lumen of the channel. But, unexpectedly, the same mutations decrease the rate of desensitization of the response, increase the apparent affinity for acetylcholine and abolish current rectification. Moreover, unlike wild-type alpha 7, which has channels with a single conductance level, the leucine-to-threonine mutant has an additional conducting state active at low acetylcholine concentrations. It is possible that mutation of Leu 247 renders conductive one of the high-affinity desensitized states of the receptor.

Rivaroxaban or Aspirin for Extended Treatment of Venous Thromboembolism

Abstract: BackgroundAlthough many patients with venous thromboembolism require extended treatment, it is uncertain whether it is better to use full- or lower-intensity anticoagulation therapy or aspirin. MethodsIn this randomized, double-blind, phase 3 study, we assigned 3396 patients with venous thromboembolism to receive either once-daily rivaroxaban (at doses of 20 mg or 10 mg) or 100 mg of aspirin. All the study patients had completed 6 to 12 months of anticoagulation therapy and were in equipoise regarding the need for continued anticoagulation. Study drugs were administered for up to 12 months. The primary efficacy outcome was symptomatic recurrent fatal or nonfatal venous thromboembolism, and the principal safety outcome was major bleeding. ResultsA total of 3365 patients were included in the intention-to-treat analyses (median treatment duration, 351 days). The primary efficacy outcome occurred in 17 of 1107 patients (1.5%) receiving 20 mg of rivaroxaban and in 13 of 1127 patients (1.2%) receiving 10 mg of ...

The Geneva affective picture database (GAPED): a new 730-picture database focusing on valence and normative significance

Abstract: In emotional research, efficient designs often rely on successful emotion induction. For visual stimulation, the only reliable database available so far is the International Affective Picture System (IAPS). However, extensive use of these stimuli lowers the impact of the images by increasing the knowledge that participants have of them. Moreover, the limited number of pictures for specific themes in the IAPS database is a concern for studies centered on a specific emotion thematic and for designs requiring a lot of trials from the same kind (e.g., EEG recordings). Thus, in the present article, we present a new database of 730 pictures, the Geneva Affective PicturE Database, which was created to increase the availability of visual emotion stimuli. Four specific negative contents were chosen: spiders, snakes, and scenes that induce emotions related to the violation of moral and legal norms (human rights violation or animal mistreatment). Positive and neutral pictures were also included: Positive pictures represent mainly human and animal babies as well as nature sceneries, whereas neutral pictures mainly depict inanimate objects. The pictures were rated according to valence, arousal, and the congruence of the represented scene with internal (moral) and external (legal) norms. The constitution of the database and the results of the picture ratings are presented.

Morphological and immunochemical differences between keloid and hypertrophic scar.

Abstract: There are two types of excessive scarring, keloid and hypertrophic scar. Contrary to hypertrophic scars, keloids do not regress with time, are difficult to revise surgically, and do not provoke scar contractures. These two lesions require different therapeutic approaches but are often confused because of an apparent lack of morphological differences. We have investigated the collagen organization and the possible presence of alpha-smooth muscle (SM) actin-expressing myofibroblasts in these conditions. Keloids contain large, thick collagen fibers composed of numerous fibrils closely packed together. In contrast hypertrophic scars exhibit modular structures in which fibroblastic cells, small vessels, and fine, randomly organized collagen fibers are present. We confirm that such nodular structures are always present in hypertrophic scar and rarely in keloid. Furthermore, only nodules of hypertrophic scars contain alpha-SM actin-expressing myofibroblasts. Electron microscopic examination supports the above-mentioned differences in collagen organization and in fibroblastic features and shows the presence of an amorphous extracellular material surrounding fibroblastic cells in keloid. The presence in hypertrophic scar myofibroblasts of alpha-SM actin, the actin isoform typical of vascular SM cells, may represent an important element in the pathogenesis of contraction. Interestingly, when placed in culture fibroblasts from hypertrophic scars and keloid express similar amounts of alpha-SM actin, suggesting that local microenvironmental factors influence in vivo the expression of this protein. Thus several morphological and immunohistochemical differences exist between hypertrophic scar and keloid that are useful for the biological and pathological characterization of the two lesions.