96 research outputs found
RÎle des protéines PII dans la régulation de l'activité et de l'état de modification de la nitrogénase chez Rhodobacter capsulatus
Mémoire numérisé par la Direction des bibliothÚques de l'Université de Montréal
RĂ©gulation du transport de glucose par le [bĂȘta]-hydroxybutyrate dans le muscle cardiaque
ThÚse numérisée par la Direction des bibliothÚques de l'Université de Montréal
Insomnia and somnolence in idiopathic RBD : a prospective cohort study
Although some sleep disorders are markers of prodromal Parkinsonâs disease and dementia with Lewy bodies, it is unclear whether
insomnia and somnolence can predict disease. We assessed a large cohort of patients with idiopathic rapid eye movement sleep
behavior disorder and age/sex matched controls, comparing the Epworth sleepiness scale, the Insomnia Severity Index, the
Pittsburgh Sleep Quality Index, and polysomnographic variables. In those with repeated scales, we assessed change over time.
Finally, we assessed whether sleep abnormalities predicted defined neurodegenerative disease. The 151 patients (age = 65.9, 75%
male) completed sleep scales and were included. Epworth scores were similar between patients and controls (7.0+/â4.6 vs. 7.2
+/â4.7, p = 0.77), and did not progress with time (change = +0.46+/â2.1, p = 0.45). Epworth scores were similar between those who
developed neurodegenerative disease and those remaining disease-free (6.7+/â4.4 vs. 7.1+/â4.7, p = 0.70). Pittsburgh Index scores
were higher in patients than controls (7.2+/â3.8 vs. 4.9+/â3.4, p = 0.004), mainly driven by the sleep disturbance/medication
components (reflecting rapid eye movement sleep behavior disorder symptoms/treatment). Baseline Pittsburgh scores did not
predict conversion to neurodegeneration, although sleep duration increased over time in those converting to neurodegenerative
disease (+0.88+/â1.32 h, p = 0.014). Insomnia index scores were higher in patients than controls (10.0+/â5.5 vs. 6.35+/â4.66, p <
0.001), but declined over time (â1.43+/â5.09, p = 0.029) particularly in those converting to neurodegenerative disease. Finally, on
polysomnogram, those with increased tonic rapid eye movement had higher risk of developing defined neurodegenerative disease
(HR = 1.88, p = 0.039). In summary, we found that somnolence and insomnia do not predict neurodegeneration in idiopathic rapid
eye movement sleep behavior disorder. As neurodegeneration progresses through prodromal stages, patients may have increasing
sleep drive and duration
Du rĂ©chauffement aux consĂ©quences Ă©cologiques : sâadapter, migrer ou disparaĂźtre?
Le rĂ©chauffement climatique est un phĂ©nomĂšne planĂ©taire menant Ă des changements dans les conditions environnementales, tels que la tempĂ©rature et la quantitĂ© de prĂ©cipitations, posant un dĂ©fi de taille pour les espĂšces sauvages. De nombreux scientifiques Ă©tudient les rĂ©ponses biologiques des plantes et des animaux face Ă ces changements. Cet article est un aperçu des connaissances scientifiques sur les stratĂ©gies et rĂ©ponses Ă©cologiques que les organismes vivants utilisent pour faire face, notamment, Ă lâaugmentation des tempĂ©ratures Ă lâĂ©chelle globale. Toutefois, pour certaines espĂšces, le rĂ©chauffement survient Ă une vitesse trop rapide, menant Ă leur disparition, et laissant parfois place Ă de nouvelles espĂšces
Changes in regional cerebral perfusion over time in idiopathic REM sleep behavior disorder
Background
Idiopathic rapid eye movement sleep behavior disorder is associated with increased risk of neurodegeneration, but the temporal evolution of regional perfusion, a marker of cerebral activity, has not been characterized. The objective of the current study was to study longitudinal regional perfusion in patients with idiopathic rapid eye movement sleep behavior disorder.
Methods
Thirtyâseven patients and 23 controls underwent highâresolution singleâphoton emission computed tomography. After 17 months on average, scans were repeated for idiopathic rapid eye movement sleep behavior disorder patients. We compared regional cerebral blood flow between groups and over time.
Results
At baseline, patients showed lower relative regional perfusion in the anterior frontal and lateral parietotemporal cortex compared with controls. However, over time, patients showed an increase in relative regional perfusion in the anterior frontal, lateral parietal, and occipitotemporal cortex, reverting toward normal control levels.
Conclusions
Patients with idiopathic rapid eye movement sleep behavior disorder showed significant areas of relative regional hypoperfusion, which disappeared over time to finally return to average levels, suggesting possible developing compensation in areas affected by neurodegeneration
Choisir Paris : les grandes donations aux musées de la Ville de Paris
La Ville de Paris est lâun des premiers collectionneurs de France. Ses quatorze musĂ©es, rĂ©unis depuis 2013 au sein de lâĂ©tablissement public Paris MusĂ©es, conservent une part importante de ce patrimoine. NĂ©es de lâintĂ©rĂȘt portĂ© par la Ville Ă sa propre mĂ©moire et Ă sa vie artistique, ces collections sont aussi le fruit du rapport passionnĂ© que de nombreux amateurs et collectionneurs ont entretenu avec la capitale, quâils ont choisie pour conserver leurs trĂ©sors patiemment assemblĂ©s. Ce « choix de Paris » rĂ©pond Ă des motifs qui, pour divers quâils soient, font sens et Ă©crivent une maniĂšre dâhistoire de lâart. Hommage aux donateurs, le colloque dont sont issus ces actes sâest donnĂ© pour objectif de mieux faire connaĂźtre cette histoire, dâĂ©clairer la genĂšse des collections des musĂ©es de la Ville de Paris et de tĂ©moigner de lâactualitĂ© de la recherche sur les grandes donations qui les ont enrichis. Ces essais tĂ©moignent aussi du souhait de Paris MusĂ©es de renforcer la recherche au sein de ses diffĂ©rentes activitĂ©s
Risk and predictors of dementia and parkinsonism in idiopathic REM sleep behaviour disorder: a multicentre study
Idiopathic REM sleep behaviour disorder (iRBD) is a powerful early sign of Parkinson's disease, dementia with Lewy bodies, and multiple system atrophy. This provides an unprecedented opportunity to directly observe prodromal neurodegenerative states, and potentially intervene with neuroprotective therapy. For future neuroprotective trials, it is essential to accurately estimate phenoconversion rate and identify potential predictors of phenoconversion. This study assessed the neurodegenerative disease risk and predictors of neurodegeneration in a large multicentre cohort of iRBD. We combined prospective follow-up data from 24 centres of the International RBD Study Group. At baseline, patients with polysomnographically-confirmed iRBD without parkinsonism or dementia underwent sleep, motor, cognitive, autonomic and special sensory testing. Patients were then prospectively followed, during which risk of dementia and parkinsonsim were assessed. The risk of dementia and parkinsonism was estimated with Kaplan-Meier analysis. Predictors of phenoconversion were assessed with Cox proportional hazards analysis, adjusting for age, sex, and centre. Sample size estimates for disease-modifying trials were calculated using a time-to-event analysis. Overall, 1280 patients were recruited. The average age was 66.3 \ub1 8.4 and 82.5% were male. Average follow-up was 4.6 years (range = 1-19 years). The overall conversion rate from iRBD to an overt neurodegenerative syndrome was 6.3% per year, with 73.5% converting after 12-year follow-up. The rate of phenoconversion was significantly increased with abnormal quantitative motor testing [hazard ratio (HR) = 3.16], objective motor examination (HR = 3.03), olfactory deficit (HR = 2.62), mild cognitive impairment (HR = 1.91-2.37), erectile dysfunction (HR = 2.13), motor symptoms (HR = 2.11), an abnormal DAT scan (HR = 1.98), colour vision abnormalities (HR = 1.69), constipation (HR = 1.67), REM atonia loss (HR = 1.54), and age (HR = 1.54). There was no significant predictive value of sex, daytime somnolence, insomnia, restless legs syndrome, sleep apnoea, urinary dysfunction, orthostatic symptoms, depression, anxiety, or hyperechogenicity on substantia nigra ultrasound. Among predictive markers, only cognitive variables were different at baseline between those converting to primary dementia versus parkinsonism. Sample size estimates for definitive neuroprotective trials ranged from 142 to 366 patients per arm. This large multicentre study documents the high phenoconversion rate from iRBD to an overt neurodegenerative syndrome. Our findings provide estimates of the relative predictive value of prodromal markers, which can be used to stratify patients for neuroprotective trials
Conservation of Salmonella Infection Mechanisms in Plants and Animals
Salmonella virulence in animals depends on effectors injected by Type III Secretion Systems (T3SSs). In this report we demonstrate that Salmonella mutants that are unable to deliver effectors are also compromised in infection of Arabidopsis thaliana plants. Transcriptome analysis revealed that in contrast to wild type bacteria, T3SS mutants of Salmonella are compromised in suppressing highly conserved Arabidopsis genes that play a prominent role during Salmonella infection of animals. We also found that Salmonella originating from infected plants are equally virulent for human cells and mice. These results indicate a high degree of conservation in the defense and infection mechanism of animal and plant hosts during Salmonella infection
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Continuation vs Discontinuation of Renin-Angiotensin System Inhibitors Before Major Noncardiac Surgery
ImportanceBefore surgery, the best strategy for managing patients who are taking renin-angiotensin system inhibitors (RASIs) (angiotensin-converting enzyme inhibitors or angiotensin receptor blockers) is unknown. The lack of evidence leads to conflicting guidelines.ObjectiveTo evaluate whether a continuation strategy vs a discontinuation strategy of RASIs before major noncardiac surgery results in decreased complications at 28 days after surgery.Design, setting, and participantsRandomized clinical trial that included patients who were being treated with a RASI for at least 3 months and were scheduled to undergo a major noncardiac surgery between January 2018 and April 2023 at 40 hospitals in France.InterventionPatients were randomized to continue use of RASIs (nâ=â1107) until the day of surgery or to discontinue use of RASIs 48 hours prior to surgery (ie, they would take the last dose 3 days before surgery) (nâ=â1115).Main outcomes and measuresThe primary outcome was a composite of all-cause mortality and major postoperative complications within 28 days after surgery. The key secondary outcomes were episodes of hypotension during surgery, acute kidney injury, postoperative organ failure, and length of stay in the hospital and intensive care unit during the 28 days after surgery.ResultsOf the 2222 patients (mean age, 67 years [SD, 10 years]; 65% were male), 46% were being treated with angiotensin-converting enzyme inhibitors at baseline and 54% were being treated with angiotensin receptor blockers. The rate of all-cause mortality and major postoperative complications was 22% (245 of 1115 patients) in the RASI discontinuation group and 22% (247 of 1107 patients) in the RASI continuation group (risk ratio, 1.02 [95% CI, 0.87-1.19]; Pâ=â.85). Episodes of hypotension during surgery occurred in 41% of the patients in the RASI discontinuation group and in 54% of the patients in the RASI continuation group (risk ratio, 1.31 [95% CI, 1.19-1.44]). There were no other differences in the trial outcomes.Conclusions and relevanceAmong patients who underwent major noncardiac surgery, a continuation strategy of RASIs before surgery was not associated with a higher rate of postoperative complications than a discontinuation strategy.Trial registrationClinicalTrials.gov Identifier: NCT03374449
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