Aerobic Training with Hyperoxia in Patients with Mild/Severe Brain Injury

Background: Previous studies have shown that aerobic training can induce physiological benefits for brain injured patients. However these benefits seem to be limited. Compared with untrained subjects who follow the same training program, patients with brain injury have a reduced exercise capacity and have difficulty in reaching a high intensity exercise level. A possible alternative to help these patients is to conduct the training in hyperoxia (O2 supply). Studies with untrained subjects have shown that training in hyperoxia enhances the fitness performance. Thus, the purpose of this study was to measure the effects of an aerobic training in hyperoxia with brain-injured patients. Methods: Twelve patients were randomly assigned to either one of two aerobic training protocols: A) 100% O2; B) 20.9% O2 (room air). In both protocols training was on stationary bicycle, 2 sessions per week over 10 weeks. Each session lasted 25 min and was composed of 6 intervals with intensity ranging from 60 to 85% of the max HR. The first interesting result is that all patients were able to reach and sustain the 80-85% level of exercise. To measure the working capacity during the training, we recorded the workload (watts) reached at the third interval (80-85% of the HRmax) of each session. Results: A difference (P < 0.05) in the power output on the ergocycle was observed between the pre test (measured on the first week) and the post test (measured on the 6th week) for subjects trained in hyperoxia but no difference was observed for subjects trained in normoxia. However, no difference was observed in the 6 min walk test for all subjects before and after the aerobic training. There was no difference in oxygen consumption (submaximal test 85% HRmax) between the pre and post tests in both groups of subjects (P=0.18). Nonetheless, subjects trained in hyperoxia showed a 16% average increase in their VO2 (85% HRmax) compared with subjects in normoxia who had a 4% average decrease. Conclusion: Our results show that oxygen supply seems to accelerate the benefits of the aerobic training with brain injured patients. We believe that it is the combination of the training protocol (i.e. intervals) and the oxygen addition that induced the early benefits observed

Txc, a new type II secretion system of Pseudomonas aeruginosa strain PA7, is regulated by the TtsS/TtsR two-component system and directs specific secretion of the CbpE chitin-binding protein.

International audienceWe present here the functional characterization of a third complete type II secretion system (T2SS) found in newly sequenced Pseudomonas aeruginosa strain PA7. We call this system Txc (third Xcp homolog). This system is encoded by the RGP69 region of genome plasticity found uniquely in strain PA7. In addition to the 11 txc genes, RGP69 contains two additional genes encoding a possible T2SS substrate and a predicted unorthodox sensor protein, TtsS (type II secretion sensor). We also identified a gene encoding a two-component response regulator called TtsR (type II secretion regulator), which is located upstream of the ttsS gene and just outside RGP69. We show that TtsS and TtsR constitute a new and functional two-component system that controls the production and secretion of the RGP69-encoded T2SS substrate in a Txc-dependent manner. Finally, we demonstrate that this Txc-secreted substrate binds chitin, and we therefore name it CbpE (chitin-binding protein E)

Word-induced postural changes reflect a tight interaction between motor and lexico-semantic representations.

International audienceA tight coupling between lexico-semantic access and motor control has been established on the basis of neuropsychological, neurophysiological, and behavioral evidence. For example, sensory and motor cortices have been shown to be active when subjects listen to words denoting bodily actions. Kinematic analyses of subjects' motor actions during the processing of linguistic stimuli provide further insights into the nature and time-course of this relationship. However, such studies have largely focused on individual body parts, in particular the upper limbs, thus neglecting the effect of language processing on lower or whole body representations. The present study bridges this gap by evaluating the interaction between linguistic processing and whole-body postural control during quiet standing. The results reveal a systematic influence of passive listening to action verbs, but not mental-state verbs, on measures of postural control, pointing to a clear and specific neural link between words conveying action concepts and whole-body motor functions

Towards a better understanding of the bacterial type II secretion pathway

The bacterial type II secretion system (T2SS) is unique in its ability to promote the transport of large folded and sometimes multimeric proteins. In this secretion process, exoproteins are first translocated into the periplasm. The final release into the medium requires a multiprotein complex called the secreton. Although the 12 individual components of the secreton have been identified, its mode of action remains obscure. We set up various dedicated in vitro and in vivo protein-protein interaction experiments to identify the Pseudomonas aeruginosa Xcp T2SS periplasmic interactome. BIAcore experiments revealed that three Xcp components, XcpP, the secretin XcpQ, and the pseudopilus tip, directly and specifically interact with secreted exoproteins. Affinity chromatography co-purification indicated that the XcpY periplasmic domain interacts with the secreted substrate and a component of the pseudopilus tip XcpW. Interestingly, the periplasmic domain of another member of the Xcp inner membrane platform, XcpZ co-elutes with the XcpY/substrate and the XcpY/ XcpW complexes during affinity chromatography. Finally the direct interaction between the secreted substrate and XcpY was confirmed by in situ photo-crosslinking. All together, our results allowed us to propose the most advanced integrative model of Xcp T2SS assembly and function

Chapitre 2. Remobiliser le corps à l’école : regards croisés

International audienceL’école est immobilité, cours d’éducation physique ou pas. La sédentarité juvénile croît et les projets pour « faire bouger » les élèves achoppent. Conjuguer mouvement humain et apprentissage serait-il impossible ? Pour diffuser des pistes de solutions, le Réseau des écoles publiques alternatives du Québec (RÉPAQ), associé à des écoles européennes « différentes » (Viaud, 2005) et à des chercheurs du Québec et de France a lancé un « Festival Bouger » vidéo. En trois minutes, des écoles partagent leurs astuces populaires pour faire apprendre et bouger les jeunes. Ces pratiques ingénieuses pourraient inspirer d’autres écoles vers une sortie de leur quasi-immobilité physique. Des chercheurs d’horizons différents ont analysé ces vidéos publiques. Dans une démarche inductive et qualitative, ils posent des repères théoriques et critiques pour mieux lire ces pratiques. Quatre perspectives de recherches émergent : apprentissage par le vécu moteur, éducation relative à l’environnement, apprentissage par corps grâce au mouvement dansé, pédagogie

Investigating the role of BCAR4 in ovarian physiology and female fertility by genome editing in rabbit

International audienceBreast Cancer Anti-estrogen Resistance 4 (BCAR4) was previously characterised in bovine species as a gene preferentially expressed in oocytes, whose inhibition is detrimental to in vitro embryo development. But its role in oogenesis, folliculogenesis and globally fertility in vivo remains unknown. Because the gene is not conserved in mice, rabbits were chosen for investigation of BCAR4 expression and function in vivo. BCAR4 displayed preferential expression in the ovary compared to somatic organs, and within the ovarian follicle in the oocyte compared to somatic cells. The transcript was detected in follicles as early as the preantral stage. Abundance decreased throughout embryo development until the blastocyst stage. A lineage of genome-edited rabbits was produced; BCAR4 expression was abolished in follicles from homozygous animals. Females of wild-type, heterozygous and homozygous genotypes were examined for ovarian physiology and reproductive parameters. Follicle growth and the number of ovulations in response to hormonal stimulation were not significantly different between genotypes. Following insemination, homozygous females displayed a significantly lower delivery rate than their heterozygous counterparts (22 ± 7% vs 71 ± 11% (mean ± SEM)), while prolificacy was 1.8 ± 0.7 vs 6.0 ± 1.4 kittens per insemination. In conclusion, BCAR4 is not essential for follicular growth and ovulation but it contributes to optimal fertility in rabbits