Sunnybrook Health Sciences Centre

About: Sunnybrook Health Sciences Centre is a healthcare organization based out in Toronto, Ontario, Canada. It is known for research contribution in the topics: Population & Medicine. The organization has 7689 authors who have published 15236 publications receiving 523019 citations. The organization is also known as: Sunnybrook.

The laryngeal mask airway and positive-pressure ventilation

Abstract: Background: The utility of the laryngeal mask airway during positive-pressure ventilation has yet to be determined. Our study was designed to assess whether significant leaks occurred with positive-pressure ventilation and if leaks were associated with gastroesophageal insufflation. Methods: Forty-eight patients undergoing elective surgery were studied. After induction of anesthesia and paralysis, controlled ventilation was used with four different peak pressure settings in each patient (15, 20, 25, and 30 cmH 2 O). The order of ventilator pressure settings was assigned from a randomized block schedule. Data collected included inspiratory and expiratory volumes, qualitative assessments of gastroesophageal insufflation, and leak at the neck. After data collection during laryngeal mask use, the anesthesiologist intubated the trachea and measurements were repeated for tracheal tube ventilation. Leak was calculated by subtracting the expiratory from the inspiratory volume and expressed as a fraction of the inspiratory volume. Results: Ventilation with the laryngeal mask airway was adequate at all ventilation pressures and comparable with tracheal tube ventilation. Leak fraction (mean±SD) at 15, 20, 25, and 30 cmH 2 O for laryngeal mask ventilation were 0.13±0.15, 0.21±0.18, 0.25±0.16 and 0.27±0.17, respectively, and 0.03±0.03, 0.05±0.03, 0.05±0.03 and 0.04±0.03, respectively, for tracheal tube ventilation. Leak fractions for ventilation with the laryngeal mask were consistently greater than those measured for tracheal tube ventilation at similar ventilation pressures. Leak fraction with laryngeal mask ventilation increased with increasing airway pressures, whereas leak with tracheal tube ventilation remained unchanged. The frequency of gastroesophageal insufflation ranged from 2.1% at a ventilation pressure of 15 cmH 2 O to 35.4% at 30 cmH 2 O. Conclusions: Ventilation using the laryngeal mask appears to be adequate if aiway resistance and pulmonary compliance are normal. Gastroesophageal insufflation of air will become a problem in the presence increased ventilation pressure

MicroRNA MiR-17 retards tissue growth and represses fibronectin expression

Abstract: MicroRNAs (miRNAs) are single-stranded regulatory RNAs, frequently expressed as clusters. Previous studies have demonstrated that the six-miRNA cluster miR-17~92 has important roles in tissue development and cancers. However, the precise role of each miRNA in the cluster is unknown. Here we show that overexpression of miR-17 results in decreased cell adhesion, migration and proliferation. Transgenic mice overexpressing miR-17 showed overall growth retardation, smaller organs and greatly reduced haematopoietic cell lineages. We found that fibronectin and the fibronectin type-III domain containing 3A (FNDC3A) are two targets that have their expression repressed by miR-17, both in vitro and in transgenic mice. Several lines of evidence support the notion that miR-17 causes cellular defects through its repression of fibronectin expression. Our single miRNA expression assay may be evolved to allow the manipulation of individual miRNA functions in vitro and in vivo. We anticipate that this could serve as a model for studying gene regulation by miRNAs in the development of gene therapy.

Current and emerging drug treatment options for Alzheimer's disease: a systematic review.

Abstract: Alzheimer's disease (AD) is a progressive and ultimately fatal condition that causes debilitating memory loss and extensive deterioration of cognitive and functional abilities. Currently available treatments for AD (donepezil, rivastigmine, galantamine and memantine) are symptomatic and do not decelerate or prevent the progression of the disease. These therapies demonstrate modest, but particularly consistent, benefit for cognition, global status and functional ability. The search for disease-modifying interventions has focused largely on compounds targeting the amyloid-β pathway. To date, the treatments targeting this pathway, such as tramiprosate and semagacestat, have been unsuccessful in demonstrating efficacy in clinical stages of testing. At this point, it is likely that not only amyloid-β aggregation but other possible neuronal mechanisms - such as hyperphosphorylated tau, neuro-inflammation and other processes - play important roles in the pathophysiology of this multifactorial disorder. Development of better disease models and biomarkers is essential for the advancement of knowledge of the disease mechanisms. This systematic review critically examines the efficacy and safety data for currently approved drugs and emerging treatments in AD, as well as discussing the present and future directions of innovation in this field.