Spontaneous neural activity changes after bariatric surgery : a resting-state fMRI study

Background: Metabolic disorders associated with obesity could lead to alterations in brain structure and function. Whether these changes can be reversed after weight loss is unclear. Bariatric surgery provides a unique oppor- tunity to address these questions because it induces marked weight loss and metabolic improvements which in turn may impact the brain in a longitudinal fashion. Previous studies found widespread changes in grey matter (GM) and white matter (WM) after bariatric surgery. However, findings regarding changes in spontaneous neural activity following surgery, as assessed with the fractional amplitude of low frequency fluctuations (fALFF) and regional homogeneity of neural activity (ReHo), are scarce and heterogenous. In this study, we used a longitu- dinal design to examine the changes in spontaneous neural activity after bariatric surgery (comparing pre- to post-surgery), and to determine whether these changes are related to cardiometabolic variables. Methods: The study included 57 participants with severe obesity (mean BMI = 43.1 ± 4.3 kg/m 2 ) who under- went sleeve gastrectomy (SG), biliopancreatic diversion with duodenal switch (BPD), or Roux-en-Y gastric bypass (RYGB), scanned prior to bariatric surgery and at follow-up visits of 4 months ( N = 36), 12 months ( N = 29), and 24 months ( N = 14) after surgery. We examined fALFF and ReHo measures across 1022 cortical and subcor- tical regions (based on combined Schaeffer-Xiao parcellations) using a linear mixed effect model. Voxel-based morphometry (VBM) based on T1-weighted images was also used to measure GM density in the same regions. We also used an independent sample from the Human Connectome Project (HCP) to assess regional differences between individuals who had normal-weight ( N = 46) or severe obesity ( N = 46). Results: We found a global increase in the fALFF signal with greater increase within dorsolateral prefrontal cortex, precuneus, inferior temporal gyrus, and visual cortex. This effect was more significant 4 months after surgery. The increase within dorsolateral prefrontal cortex, temporal gyrus, and visual cortex was more limited after 12 months and only present in the visual cortex after 24 months. These increases in neural activity measured by fALFF were also significantly associated with the increase in GM density following surgery. Furthermore, the in- crease in neural activity was significantly related to post-surgery weight loss and improvement in cardiometabolic variables, such as blood pressure. In the independent HCP sample, normal-weight participants had higher global and regional fALFF signals, mainly in dorsolateral/medial frontal cortex, precuneus and middle/inferior temporal gyrus compared to the obese participants. These BMI-related differences in fALFF were associated with the in- crease in fALFF 4 months post-surgery especially in regions involved in control, default mode and dorsal attention networks. Conclusions: Bariatric surgery-induced weight loss and improvement in metabolic factors are associated with widespread global and regional increases in neural activity, as measured by fALFF signal. These findings along- side the higher fALFF signal in normal-weight participants compared to participants with severe obesity in an independent dataset suggest an early recovery in the neural activity signal level after the surgery

Mémento 2 : Résidences 1999-2000

This richly illustrated catalogue documents the work of 35 artists who took part in six residencies (including two events - La Cueillette and La Ruche) that took place in 1999 and 2000 at Centre Est-Nord-Est. The centre’s director, F. Michel, describes the nature and purpose of the residencies as well as that of the catalogue : to reflect each participant’s experience. Includes brief comments by the artist on their work and on their stay. Text in French and English. Biographical notes

Social circus program (Cirque du Soleil) promoting social participation of young people living with physical disabilities in transition to adulthood : a qualitative pilot study

Purpose: To explore the perceived impact of a social circus program on the participation level of young adults’ living with physical disabilities from their own and their parents’ perspective. Method: Exploratory phenomenological qualitative design. A social circus program was offered for nine months. Perceived participation level was documented through pre and post semi-structured interviews. A pretested interview guide was used. Interviews were transcribed and coded by two independent researchers. Results: The average age of the participants (n = 9) was 20.0 ± 1.4 years with 2/9 being female. Participation was perceived as being improved after the intervention from both perspectives (participants and parents) mainly for communication, mobility, relationships, community life and responsibilities. The intervention was perceived as strengthening self-perception and self-efficacy, which in turn enhanced participation level and decreased parents’ bounding. Conclusion: The results show promises for social circus as a new approach in adult physical rehabilitation for this population in transition

Impact of maternal cardiometabolic status after bariatric surgery on the association between telomere length and adiposity in offspring

Abstract The impact of bariatric surgery on metabolic and inflammatory status are reflected in the epigenetic profile and telomere length mediated by the changes in the metabolic status of the patients. This study compared the telomere length of children born before versus after maternal bariatric surgery as a surrogate to test the influence of the mother’s metabolic status on children’s telomere length. DNA methylation telomere length (DNAmTL) was estimated from Methylation-EPIC BeadChip array data from a total of 24 children born before and after maternal bariatric surgery in the greater Quebec City area. DNAmTL was inversely associated with chronological age in children (r = − 0.80, p < 0.001) and significant differences were observed on age-adjusted DNAmTL between children born before versus after the maternal bariatric surgery. The associations found between body mass index and body fat percentage with DNAmTL in children born after the surgery were influenced by maternal triglycerides, TG/HDL-C ratio and TyG index. This study reports the impact of maternal bariatric surgery on offspring telomere length. The influence of maternal metabolic status on the association between telomere length and markers of adiposity in children suggests a putative modulating effect of bariatric surgery on the cardiometabolic risk in offspring

Les cahiers de l'IRIPI 3 - Pratiques inclusives en contexte de diversité dans les milieux d’enseignement

Actes du colloque virtuel tenu les 26 et 27 novembre 2020, publiés sous la direction de Habib El-Hage, directeur de l'IRIPI

<b>IL-6 trans-signaling is increased in diabetes, impacted by glucolipotoxicity and associated with liver stiffness and fibrosis in fatty liver disease</b>

Many people living with diabetes also have non-alcoholic fatty liver disease (NAFLD). Interleukin-6 (IL-6) is involved in both diseases, interacting with both membrane-bound (classical) and circulating soluble receptors (trans-signaling). We investigated whether secretion of IL-6 trans-signaling co-receptors are altered in NAFLD by diabetes, and whether this might associate with the severity of fatty liver disease. Secretion patterns were investigated using human hepatocyte, stellate and monocyte cell lines. Associations with liver pathology were investigated in two patient cohorts: 1) biopsy-confirmed NASH and 2) class 3 obesity. We found that exposure of stellate cells to high glucose and palmitate increased IL-6 and sgp130 secretion. In line with this, plasma sgp130 in both patient cohorts positively correlated with HbA1c, and subjects with diabetes had higher circulating levels of IL-6 and trans-signaling co-receptors. Plasma sgp130 strongly correlated with liver stiffness and was significantly increased in subjects with F4 fibrosis stage. Monocyte activation was associated with reduced sIL-6R secretion. These data suggest that the hyperglycemia and hyperlipidemia can directly impact IL-6 trans-signaling, and that this may be linked to enhanced severity of NAFLD in patients with concomitant diabetes.</p