Connectomes across development reveal principles of brain maturation.

An animal's nervous system changes as its body grows from birth to adulthood and its behaviours mature1-8. The form and extent of circuit remodelling across the connectome is unknown3,9-15. Here we used serial-section electron microscopy to reconstruct the full brain of eight isogenic Caenorhabditis elegans individuals across postnatal stages to investigate how it changes with age. The overall geometry of the brain is preserved from birth to adulthood, but substantial changes in chemical synaptic connectivity emerge on this consistent scaffold. Comparing connectomes between individuals reveals substantial differences in connectivity that make each brain partly unique. Comparing connectomes across maturation reveals consistent wiring changes between different neurons. These changes alter the strength of existing connections and create new connections. Collective changes in the network alter information processing. During development, the central decision-making circuitry is maintained, whereas sensory and motor pathways substantially remodel. With age, the brain becomes progressively more feedforward and discernibly modular. Thus developmental connectomics reveals principles that underlie brain maturation.

External Beam Radiation Therapy in pT4 Well-Differentiated Thyroid Cancer: A Population-Based Study of 405 Patients.

PURPOSE: The benefit of external beam radiation therapy (EBRT) in locally advanced, well- differentiated thyroid cancer (WDTC) is uncertain. The purpose of this study is to evaluate locoregional recurrence (LRR), progression-free survival, and cause-specific survival (CSS) of patients with pT4 well-differentiated thyroid carcinoma. METHODS AND MATERIALS: A population-based retrospective review was conducted of consecutive patients with pT4 WDTC (per the American Joint Committee on Cancer, 8th edition, criteria) treated provincially between 1985 and 2013. The primary endpoints were cumulative incidence of LRR and CSS. To account for the competing risks of death from other causes, a Fine-Gray's test was used. A Cox-proportional hazards model was used to analyze overall survival (OS). Multivariate models and propensity matching were used to account for the effects of covariates. RESULTS: A total of 405 patients were identified with a median follow-up time of 14.3 years for a total of 4209 person-years of follow up. The median age at the time of diagnosis was 53 years (range, 20-87). There were 211 patients (52%) who received EBRT. EBRT was associated with age ≥55 years (56% vs 35%; P < .001), airway involvement (42% vs 8%; P < .001), and R1/2 resection (81% vs 51%; P < .001). The 10-year outcomes for the non-EBRT and EBRT groups were 21.6% versus 11.4%, respectively, for LRR, 84.1% versus 93.1%, respectively, for CSS, and 85.7% versus 67.5%, respectively, for OS. On multivariate analysis, EBRT was associated with a lower rate of LRR (hazard ratio [HR]: 0.334; P < .001), but not associated with CSS (HR: 1.56; P = .142) nor OS (HR: 1.216; P = .335). After propensity score matching, the EBRT cohort had lower rates of LRR relative to the non-EBRT cohort (HR: 0.261; P = .0003), but there were no differences in CSS or OS. CONCLUSIONS: In this large, population-based analysis of patients with pT4 WDTC, EBRT was associated with lower rates of LRR, but no difference in CSS or OS.

Cancellation of elective surgery: rates, reasons and effect on patient satisfaction.

Background: The cancellation of elective surgeries is a major problem that increases wait times, exacerbates costs and can negatively affect patients, both psychologically and physically. Our objectives were to investigate the reasons for cancellations across specialties at a single centre, to compare these reasons with previous data from the same centre between 2005 and 2009 and to examine how cancellations affected patients' lives and views of the medical system in cases when the cancellations were potentially preventable. Methods: Cancellation records of all elective surgeries scheduled between June 1, 2012, and Jan. 31, 2016, at a medium-sized, tertiary care, academic centre were retrospectively reviewed. We evaluated the rates and reasons for cancellation and interviewed a subset of patients whose surgery was cancelled for a potentially preventable reason (i.e., operating room running late, bed shortage, emergency case took place of scheduled surgery). Results: Across 11 surgical specialties, 2933 of 20 881 surgeries (14.0%) were cancelled and of these, 2448 (83.5%) were for administrative or structural reasons. Compared with the data collected previously for general, gynecological and urological procedures, cancellation rates increased from 8.1% to 11.8%. Although patients reported inconvenience, they were generally satisfied with the availability and the quality of the health care they received. Conclusion: Consistent with the previous study, our data suggest that most cancellations occur because of administrative or structural processes that are potentially preventable. Targeting these processes may help to reduce cancellations for elective surgeries and thereby improve economic efficiency and patient outcomes.

Contexte: L'annulation des chirurgies électives est un problème majeur qui allonge les temps d'attente, fait gonfler les coûts et peut affecter négativement les patients, tant psychologiquement que physiquement. Nos objectifs étaient de découvrir les raisons des annulations dans les diverses spécialités d'un seul centre, afin de comparer ces raisons à des données antérieures du même centre recueillies entre 2005 et 2009 et d'examiner en quoi les annulations affectent la vie des patients et leur perception du système médical dans les cas où les annulations auraient pu être évitées. Méthodes: Les dossiers d'annulation de toutes les chirurgies électives entre le 1er juin 2012 et le 31 janvier 2016 dans un centre hospitalier universitaire de soins tertiaires de taille moyenne ont été analysés de manière rétrospective. Nous avons évalué les taux d'annulation et les motifs, et interrogé un groupe de patients dont la chirurgie a été annulée pour des raisons potentiellement évitables (p. ex., retards au bloc opératoire, manque de lits, priorisation de cas plus urgents). Résultats: Entre les 11 spécialités chirurgicales, 2933 des 20 881 chirurgies (14,0 %) ont été annulées et parmi elles, 2448 (83,5 %) pour des raisons administratives ou structurelles. Comparativement aux données précédemment recueillies pour les interventions générales, gynécologiques et urologiques, les taux d'annulation ont augmenté de 8,1 % à 11,8 %. Même si les patients ont déploré des inconvénients, ils se sont généralement déclarés satisfaits de la qualité des soins reçus et de leur accessibilité. Conclusion: Comme lors de l'étude précédente, nos données suggèrent que les causes les plus fréquentes d'annulation sont liées à des marches à suivre administratives ou structurelles qui sont potentiellement évitables. Cibler ces marches à suivre pourrait contribuer à réduire le nombre d'annulations de chirurgies électives et améliorer de ce fait l'efficience économique et les résultats chez les patients.