Diurnal or circadian rhythms are fundamentally important for healthy cardiovascular physiology and play a role in timing of onset and tolerance to myocardial infarction (MI) in patients. Whether time of day of MI triggers different molecular and cellular responses that can influence myocardial remodeling is not known. This study was designed to test whether time of day of MI triggers different gene expression, humoral, and innate inflammatory responses that contribute to cardiac repair after MI. Mice were infarcted by left anterior descending coronary artery ligation (MI model) within a 2-h time window either shortly after lights on or lights off, and the early remodeling responses at 8 h postinfarction were examined. We found that sleep-MI preferentially triggers early expression of genes associated with inflammatory responses, whereas wake-MI triggers more genes associated with metabolic pathways and transcription/translation, by microarray analyses. Homozygous clock mutant mice exhibit altered diurnal gene expression profiles, consistent with their cycling before onset of MI. In the first 8 h, crucial for innate immune responses to MI, there are also significant differences in sleep-MI and wake-MI serum cytokine responses and in neutrophil infiltration to infarcted myocardium. By 1-wk post-MI, there are differences in survivorship between the sleep and wake MI mice that could be explained by the different molecular and cellular responses. Our whole body physiology, tissues, and cells exhibit endogenous daily rhythms, and understanding their role in triggering effective responses after MI could lead to new strategies to benefit patients with cardiovascular disease.

OBJECT Although intracranial arachnoid cysts are a common incidental finding on pediatric brain imaging, only a subset of patients require surgery for them. For the minority who undergo surgery, the comparative effectiveness of various surgical approaches is debated. The authors explored predictors of surgery and compared operative techniques for pediatric patients with an intracranial arachnoid cyst seen at a tertiary care center. METHODS The authors reviewed records of pediatric patients with an intracranial arachnoid cyst. For each patient, data on baseline characteristics, the method of intervention, and surgical outcomes for the initial surgery were extracted, and cyst size at diagnosis was calculated (anteroposterior × craniocaudal × mediolateral). Baseline variables were analyzed as predictors of surgery by using logistic regression modeling, excluding patients whose surgery was not related to cyst size (i.e., those with obstructive hydrocephalus secondary to the cyst compressing a narrow CSF flow pathway or cyst rupture/hemorrhage). Data collected regarding surgical outcomes were analyzed descriptively. RESULTS Among 83 pediatric patients with an intracranial arachnoid cyst seen over a 25-year period (1989–2013), 27 (33%) underwent surgery; all had at least 1 cyst-attributed symptom/finding. In the multivariate model, age at presentation and cyst size at diagnosis were independent predictors of surgery. Cyst size had greater predictive value; specifically, the area under the curve for the receiver-operating-characteristic curve was 0.89 (95% CI 0.82–0.97), with an ideal cutoff point of ≥ 68 cm3. This cutoff point had 100% sensitivity (95% CI 79%–100%), 75% specificity (95% CI 61%–85%), a 53% positive predictive value (95% CI 36%–70%), and a 100% negative predictive value (95% CI 91%–100%); the positive likelihood ratio was 4.0 (95% CI 2.5–6.3), and the negative likelihood ratio was 0 (95% CI 0–0.3). Although the multivariate model excluded 7 patients who underwent surgery (based on prespecified criteria), excluding these 7 cases did not change the overall findings, as shown in a sensitivity analysis that included all the cases. Descriptive results regarding surgical outcomes did not indicate any salient differences among the surgical techniques (endoscopic fenestration, cystoperitoneal shunting, or craniotomy-based procedures) in terms of symptom resolution within 6 months, need for reoperation to date, cyst-size change from before the operation, morbidity, or mortality. CONCLUSIONS The results of these exploratory analyses suggest that pediatric patients with an intracranial arachnoid cyst are more likely to undergo surgery if the cyst is large, compresses a narrow CSF flow pathway to cause hydrocephalus, or has ruptured/hemorrhaged. There were no salient differences among the 3 surgical techniques for several clinically important outcomes. A prospective multicenter study is required to enable more robust analyses, which could ultimately provide a decision-making framework for surgical indications and clarify any differences in the comparative effectiveness of surgical approaches to treating pediatric intracranial arachnoid cysts.

Background Critical care research coordinators implement study protocols in intensive care units, yet little is known about their experiences. Objective To identify the responsibilities, stressors, motivators, and job satisfaction of critical care research coordinators in Canada. Methods Responses to a self-administered survey were collected in order to identify and understand factors that motivate and stress research coordinators and enhance their job satisfaction. Items were generated in 5 domains (demographics, job responsibilities, stressors, motivators, and satisfaction). Face validity pretesting was conducted and clinical sensibility was evaluated. Items were rated on 5-point Likert scales. Descriptive analyses were used to report results. Results The response rate was 78% (66 of 85). Most critical care research coordinators (71%) were employed full time; they were engaged in 9 studies (7 academic, 2 industry); and 49% were nurses. Of 30 work responsibilities, the most frequently cited were submitting ethics applications (89%), performing data entry (89%), and attending meetings (87%). Highest-rated stressors were unrealistic workload and weekend/holiday screening; highest-rated motivators were a positive work environment and team spirit. Overall, 26% were “very satisfied” and 53% were “satisfied” with their jobs. Conclusions Critical care research coordinators in Canada indicate that, despite significant work responsibilities, they are satisfied with their jobs thanks to positive work environments and team spirit.

This study demonstrates that coiling-related complications of elective endovascular coiling tend to occur either intraoperatively or are detected shortly after reversal of anesthesia. Further investigation with a larger cohort may help to guide important preoperative communication with patients and identify a select group of patients who may not necessarily require prolonged admission to hospital for observation.

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Hemangiomas are customarily described as low-grade vascular tumors most often located in the head and neck, but on rare occasions occurring in the intradural space of the spine. The different subtypes of hemangiomas can be distinguished histologically as capillary, cavernous, or mixed types. We describe a rare case of a mixed capillary-cavernous extramedullary intradural hemangioma of the thoracic spinal cord, mimicking meningioma radiologically.

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Our survey is an up to date description of current practice patterns for ACD amongst Canadian neurosurgeons.