195 research outputs found
Les services intensifs : une nouvelle approche dans lâintervention auprĂšs des familles Ă risque
L'augmentation du nombre de placements d'enfants et l'Ă©chec relatif de cette mesure dans le traitement des problĂšmes familiaux amĂšnent les professionnels des services sociaux Ă rĂ©flĂ©chir sur de nouvelles façons d'aider les familles Ă rĂ©soudre leurs difficultĂ©s tout en maintenant l'unitĂ© familiale intacte. Les services intensifs Ă la famille appartiennent Ă ce courant de renouveau. Le prĂ©sent article dĂ©crit cette nouvelle forme d'intervention. Plus prĂ©cisĂ©ment, trois grands thĂšmes sont abordĂ©s. Le premier porte sur l'historique de ces programmes, leur philosophie et leurs principes, de mĂȘme que sur les trois principaux modĂšles mis en oeuvre sous le vocable des services intensifs Ă la famille, soit les programmes Homebuilders, Familieset Family Treatment. Dans un second temps, l'efficacitĂ© des programmes de sauvegarde de la famille est examinĂ©e en apportant une attention particuliĂšre aux problĂšmes mĂ©thodologiques que soulĂšve leur Ă©valuation. L'article se termine par une prĂ©sentation des conditions nĂ©cessaires Ă l'implantation de ces programmes dans les services sociaux quĂ©bĂ©cois
Fast pyrolysis of contaminated biomass: The chemical and thermodynamic description of the intermediate liquid compound
Please click Additional Files below to see the full abstrac
EEG functional connectivity prior to sleepwalking : evidence of interplay between sleep and wakefulness
Study Objectives: Although sleepwalking (somnambulism) affects up to 4% of adults, its pathophysiology remains poorly understood. Sleepwalking can be
preceded by fluctuations in slow-wave sleep EEG signals, but the significance of these pre-episode changes remains unknown and methods based on EEG
functional connectivity have yet to be used to better comprehend the disorder.
Methods: We investigated the sleep EEG of 27 adult sleepwalkers (mean age: 29 ± 7.6 years) who experienced a somnambulistic episode during slow-wave
sleep. The 20-second segment of sleep EEG immediately preceding each patientâs episode was compared with the 20-second segment occurring 2 minutes
prior to episode onset.
Results: Results from spectral analyses revealed increased delta and theta spectral power in the 20 seconds preceding the episodesâ onset as compared to
the 20 seconds occurring 2 minutes before the episodes. The imaginary part of the coherence immediately prior to episode onset revealed (1) decreased delta
EEG functional connectivity in parietal and occipital regions, (2) increased alpha connectivity over a fronto-parietal network, and (3) increased beta connectivity
involving symmetric inter-hemispheric networks implicating frontotemporal, parietal and occipital areas.
Conclusions: Taken together, these modifications in EEG functional connectivity suggest that somnambulistic episodes are preceded by brain processes
characterized by the co-existence of arousal and deep slee
The serine protease inhibitor serpinE2 is a novel target of ERK signaling involved in human colorectal tumorigenesis
<p>Abstract</p> <p>Background</p> <p>Among the most harmful of all genetic abnormalities that appear in colorectal cancer (CRC) development are mutations of KRAS and its downstream effector BRAF as they result in abnormal extracellular signal-related kinase (ERK) signaling. In a previous report, we had shown that expression of a constitutive active mutant of MEK1 (caMEK) in normal rat intestinal epithelial cells (IECs) induced morphological transformation associated with epithelial to mesenchymal transition, growth in soft agar, invasion and metastases in nude mice. Results from microarrays comparing control to caMEK-expressing IECs identified the gene encoding for serpinE2, a serine protease inhibitor, as a potential target of activated MEK1.</p> <p>Results</p> <p>1- RT-PCR and western blot analyses confirmed the strong up-regulation of serpinE2 expression and secretion by IECs expressing oncogenic MEK, Ras or BRAF. 2- Interestingly, serpinE2 mRNA and protein were also markedly enhanced in human CRC cells exhibiting mutation in <it>KRAS </it>and <it>BRAF</it>. 3- RNAi directed against serpinE2 in caMEK-transformed rat IECs or in human CRC cell lines HCT116 and LoVo markedly decreased foci formation, anchorage-independent growth in soft agarose, cell migration and tumor formation in nude mice. 4- Treatment of CRC cell lines with U0126 markedly reduced <it>serpinE2 </it>mRNA levels, indicating that expression of <it>serpinE2 </it>is likely dependent of ERK activity. 5- Finally, Q-PCR analyses demonstrated that mRNA levels of serpinE2 were markedly increased in human adenomas in comparison to healthy adjacent tissues and in colorectal tumors, regardless of tumor stage and grade.</p> <p>Conclusions</p> <p>Our data indicate that serpinE2 is up-regulated by oncogenic activation of Ras, BRAF and MEK1 and contributes to pro-neoplastic actions of ERK signaling in intestinal epithelial cells. Hence, serpinE2 may be a potential therapeutic target for colorectal cancer treatment.</p
Gray matter hypertrophy and thickening with obstructive sleep apnea in middle-aged and older adults
Rationale: Obstructive sleep apnea causes intermittent hypoxemia, hemodynamic fluctuations,
and sleep fragmentation, all of which could damage cerebral gray matter that can be indirectly
assessed with neuroimaging.
Objectives: To investigate whether markers of obstructive sleep apnea severity are associated
with gray matter changes among middle-aged and older individuals.
Methods: Seventy-one subjects (ages: 55 to 76; apneaâhypopnea index: 0.2 to 96.6 events/h)
were evaluated with magnetic resonance imaging. Two techniques were used: 1) voxel-based
morphometry, which measures gray matter volume and concentration; 2) FreeSurfer automated
segmentation, which estimates the volume of predefined cortical/subcortical regions and cortical
thickness. Regression analyses were performed between gray matter characteristics and markers
of obstructive sleep apnea severity (hypoxemia, respiratory disturbances, sleep fragmentation).
Measurements and Main Results: Subjects had few symptoms, i.e. sleepiness, depression,
anxiety and cognitive deficits. While no association was found with voxel-based morphometry,
FreeSurfer revealed increased gray matter with obstructive sleep apnea. Higher levels of
hypoxemia correlated with increased volume and thickness of the left lateral prefrontal cortex as
well as increased thickness of the right frontal pole, the right lateral parietal lobules, and the left
posterior cingulate cortex. Respiratory disturbances positively correlated with right amygdala
volume while more severe sleep fragmentation was associated with increased thickness of the
inferior frontal gyrus.
Conclusions: Gray matter hypertrophy and thickening were associated with hypoxemia,
respiratory disturbances, and sleep fragmentation. These structural changes in a group of middle-aged and older individuals may represent adaptive/reactive brain mechanisms attributed to a
presymptomatic stage of obstructive sleep apnea
BDNF Val66Met polymorphism interacts with sleep consolidation to predict ability to create new declarative memories
It is hypothesized that a fundamental function of sleep is to restore an individual's day-to-day ability to learn and to constantly adapt to a changing environment through brain plasticity. Brain-derived neurotrophic factor (BDNF) is among the key regulators that shape brain plasticity. However, advancing age and carrying the BDNF Met allele were both identified as factors that potentially reduce BDNF secretion, brain plasticity, and memory. Here, we investigated the moderating role of BDNF polymorphism on sleep and next-morning learning ability in 107 nondemented individuals who were between 55 and 84 years of age. All subjects were tested with 1 night of in-laboratory polysomnography followed by a cognitive evaluation the next morning. We found that in subjects carrying the BDNF Val66Val polymorphism, consolidated sleep was associated with significantly better performance on hippocampus-dependent episodic memory tasks the next morning (ÎČ-values from 0.290 to 0.434, p †0.01). In subjects carrying at least one copy of the BDNF Met allele, a more consolidated sleep was not associated with better memory performance in most memory tests (ÎČ-values from -0.309 to -0.392, p values from 0.06 to 0.15). Strikingly, increased sleep consolidation was associated with poorer performance in learning a short story presented verbally in Met allele carriers (ÎČ = -0.585, p = 0.005). This study provides new evidence regarding the interacting roles of consolidated sleep and BDNF polymorphism in the ability to learn and stresses the importance of considering BDNF polymorphism when studying how sleep affects cognition
Obstructive sleep apnea during REM sleep and daytime cerebral functioning : a regional cerebral blood flow study using high-resolution SPECT
Obstructive sleep apnea (OSA) predominantly during rapid eye movement (REM) sleep may have impacts on brain health, even in milder OSA cases. Here, we evaluated whether REM sleep OSA is associated with abnormal daytime cerebral functioning using high-resolution single-photon emission computed tomography (SPECT). We tested 96 subjects (25 F, age: 65.2â±â6.4) with a wide range of OSA severity from no OSA to severe OSA (apneaâhypopnea index: 0â97 events/h). More respiratory events during REM sleep were associated with reduced daytime regional cerebral blood flow (rCBF) in the bilateral ventromedial prefrontal cortex and in the right insula extending to the frontal cortex. More respiratory events during non-REM (NREM) sleep were associated with reduced daytime rCBF in the left sensorimotor and temporal cortex. In subjects with a lower overall OSA severity (apneaâhypopnea index<15), more respiratory events during REM sleep were also associated with reduced daytime rCBF in the insula and extending to the frontal cortex. Respiratory events that characterized OSA during NREM versus REM sleep are associated with distinct patterns of daytime cerebral perfusion. REM sleep OSA could be more detrimental to brain health, as evidenced by reduced daytime rCBF in milder forms of OSA
Cerebral white matter diffusion properties and freeâwater with obstructive sleep apnea severity in older adults
Characterizing the effects of obstructive sleep apnea (OSA) on the aging brain could be key in our understanding of neurodegeneration in this population. Our objective was to assess white matter properties in newly diagnosed and untreated adults with mild to severe OSA. Sixtyâfive adults aged 55 to 85 were recruited and divided into three groups: control (apneaâhypopnea index â€5/hr; n = 18; 65.2â±â7.2âyears old), mild (>5 to â€15 hr; n = 27; 64.2â±â5.3âyears old) and moderate to severe OSA (>15/hr; n = 20; 65.2â±â5.5âyears old). Diffusion tensor imaging metrics (fractional anisotropy (FA), axial diffusivity (AD), radial diffusivity, and mean diffusivity) were compared between groups with TractâBased Spatial Statistics within the white matter skeleton created by the technique. Groups were also compared for white matter hyperintensities volume and the freeâwater (FW) fraction. Compared with controls, mild OSA participants showed widespread areas of lower diffusivity (pâ<â.05 corrected) and lower FW fraction (pâ<â.05). Participants with moderate to severe OSA showed lower AD in the corpus callosum compared with controls (pâ<â.05 corrected). No betweenâgroup differences were observed for FA or white matter hyperintensities. Lower white matter diffusivity metrics is especially marked in mild OSA, suggesting that even the milder form may lead to detrimental outcomes. In moderate to severe OSA, competing pathological responses might have led to partial normalization of diffusion metrics
Reduced rapid eye movement sleep in late middle-aged and older apolipoprotein E É4 allele carriers
Study Objectives
Apolipoprotein E É4 (APOE4) is the strongest genetic risk factor for Alzheimerâs disease (AD). In addition, APOE4 carriers may exhibit sleep disturbances, but conflicting results have been reported, such that there is no clear consensus regarding which aspects of sleep are impacted. Our objective was to compare objective sleep architecture between APOE4 carriers and non-carriers, and to investigate the modulating impact of age, sex, cognitive status, and obstructive sleep apnea (OSA).
Methods
A total of 198 dementia-free participants aged >55 years old (mean age: 68.7 ± 8.08 years old, 40.91% women, 41 APOE4 carriers) were recruited in this cross-sectional study. They underwent polysomnography, APOE4 genotyping, and a neuropsychological evaluation. ANCOVAs assessed the effect of APOE4 status on sleep architecture, controlling for age, sex, cognitive status, and the apneaâhypopnea index. Interaction terms were added between APOE4 status and covariates.
Results
Rapid eye movement (REM) sleep percentage (Fâ
=â
9.95, pâ
=â
.002, ηp2â
=â
0.049) and duration (Fâ
=â
9.23, pâ
=â
.003, ηp2â
=â
0.047) were lower in APOE4 carriers. The results were replicated in a subsample of 112 participants without moderate-to-severe OSA. There were no significant interactions between APOE4 status and age, sex, cognitive status, and OSA in the whole sample.
Conclusions
Our results show that APOE4 carriers exhibit lower REM sleep duration, including in cognitively unimpaired individuals, possibly resulting from early neurodegenerative processes in regions involved in REM sleep generation and maintenance
- âŠ