Δ-9-Tetrahydrocannabinol and Cannabidiol produce dissociable effects on prefrontal cortical executive function and regulation of affective behaviors.

The use of cannabis for therapeutic and recreational purposes is growing exponentially. Nevertheless, substantial questions remain concerning the potential cognitive and affective side-effects associated with cannabis exposure. In particular, the effects of specific marijuana-derived phytocannabinoids on neural regions such as the prefrontal cortex (PFC) are of concern, given the role of the PFC in both executive cognitive function and affective processing.

Infusions of Nerve Growth Factor Into the Developing Frontal Cortex Leads to Deficits in Behavioral Flexibility and Increased Perseverance.

In the pursuit of further establishing a neurodevelopmental animal model to investigate the mechanisms underlying impaired executive function, a core and severely debilitating symptom of schizophrenia, we sought to characterize the deficits in behavioral flexibility in adult rats following neonatal infusions of nerve growth factor (NGF) into the medial part of the developing frontal cortex. Our previous studies using this neonatal frontal cortical lesion model have shown that it leads to adult-onset positive and negative symptom-like features, and several neuropathological abnormalities of schizophrenia. In the present study, we used operant conditioning-based paradigms to investigate set-shifting ability and reversal learning performance in adult rats that received infusions of NGF into the developing frontal cortex on post-natal day 1.

Behavioural inflexibility in a comorbid rat model of striatal ischemic injury and mutant hAPP overexpression.

Alzheimer disease (AD) and stroke coexist and interact; yet how they interact is not sufficiently understood. Both AD and basal ganglia stroke can impair behavioural flexibility, which can be reliably modeled in rats using an established operant based set-shifting test. Transgenic Fischer 344-APP21 rats (TgF344) overexpress pathogenic human amyloid precursor protein (hAPP) but do not spontaneously develop overt pathology, hence TgF344 rats can be used to model the effect of vascular injury in the prodromal stages of Alzheimer disease.

Outcomes of After-Hours Hip Fracture Surgery.

Background: Given single-institution studies showing trends between after-hours hip fracture surgical procedures and adverse outcomes, as well as fixation time targets that may increasingly compel after-hours operations, we investigated the relationship between after-hours hip fracture surgical procedures and adverse outcomes in a large, population-based cohort.

Methods: All Ontarians who were ≥60 years of age and underwent a hip fracture surgical procedure between April 2002 and March 2014 were eligible for study inclusion. Data were obtained from linked health administrative databases.

Combination of behaviorally sub-effective doses of glutamate NMDA and dopamine D receptor antagonists impairs executive function.

Impairment of executive function is a core feature of schizophrenia. Preclinical studies indicate that injections of either N-methyl d-aspartate (NMDA) or dopamine D receptor blockers impair executive function. Despite the prevailing notion based on postmortem findings in schizophrenia that cortical areas have marked suppression of glutamate and dopamine, recent in vivo imaging studies suggest that abnormalities of these neurotransmitters in living patients may be quite subtle.

Quality of Life in Bilateral Vs. Unilateral End-Stage Ankle Arthritis and Outcomes of Bilateral Vs. Unilateral Total Ankle Replacement.

Background: We performed a retrospective cohort study to compare preoperative health-related quality of life (HRQoL) between patients with bilateral and those with unilateral end-stage ankle arthritis. We also compared midterm outcomes in a subgroup of patients who had undergone staged bilateral total ankle replacement (TAR) with the outcomes in the group treated with unilateral TAR.

Methods: The HRQoL before surgical treatment was compared between 53 patients with bilateral end-stage ankle arthritis identified from the Canadian Orthopaedic Foot and Ankle Society Prospective Ankle Reconstruction Database and 106 patients with unilateral arthritis selected from the same database.

Hemiarthroplasty of the elbow: the effect of implant size on joint congruency.

Background: Distal humeral hemiarthroplasty is a treatment option for elbow joint disease that predominantly affects the distal humerus, including distal humerus fractures, nonunions, and avascular necrosis. The effect of hemiarthroplasty implants on joint contact has not been reported. The purpose of this in vitro study was to quantify the effects of hemiarthroplasty and implant size on ulnohumeral joint congruency.

Factors affecting transfusion requirement after hip fracture: can we reduce the need for blood?

Background: Hip fractures are common injuries that result in blood loss and frequently require the transfusion of blood products. We sought to identify risk factors leading to increased blood transfusion in patients presenting with hip fractures, especially those factors that are modifiable.

Methods: We retrospectively reviewed the cases of all patients who had fixation of their hip fractures between October 2005 and February 2010.

Hemiarthroplasty of the elbow: the effect of implant size on kinematics and stability.

Background: Distal humeral hemiarthroplasty is a treatment option for distal humeral fractures, nonunions, and avascular necrosis. The biomechanical effects, however, have not been reported. The purpose of this in vitro study was to quantify the effects of hemiarthroplasty and implant size on elbow joint kinematics.

An anthropometric study of the distal humerus.

Background: The optimal articular shape for distal humeral hemiarthroplasty has not been defined because of a paucity of data quantifying the morphology of the normal distal humerus. This study defines the osseous anatomy and anatomic variability of the distal humerus using 3-dimensional imaging techniques.

Methods: Three-dimensional surface models were created from computed tomography scans obtained from 50 unpaired human cadaveric elbows.

A comparison of surgical delays in directly admitted versus transferred patients with hip fractures: opportunities for improvement?

Background: The increasing incidence of hip fractures in our aging population challenges orthopedic surgeons and hospital administrators to effectively care for these patients. Many patients present to regional hospitals and are transferred to tertiary care centres for surgical management, resulting in long delays to surgery. Providing timely care may improve outcomes, as delay carries an increased risk of morbidity and mortality.

A simple and economical method of electrode fabrication for brain self-stimulation in rats.

Introduction: Intracranial self-stimulation (ICSS) is an operant paradigm in which rodents self-administer rewarding electrical stimulation through electrodes implanted into the brain. We describe a simple, inexpensive and reliable method to fabricate monopolar and bipolar electrodes, along with the swivel system, for delivery of electric pulses at the targeted sites in the brain of rat.

Methods: The system consists of an insulated stainless steel wire(s) (diameter: 0.

NPY mediates reward activity of morphine, via NPY Y1 receptors, in the nucleus accumbens shell.

Although the interaction between endogenous neuropeptide Y (NPY) and opioidergic systems in processing of reward has been speculated, experimental evidence is lacking. We investigated the role of NPY, and its Y1 receptors, in the nucleus accumbens shell (AcbSh) in morphine induced reward and reinforcement behavior. Rats were implanted with cannulae targeted at AcbSh for drug administration, and with stimulating electrode in the medial forebrain bundle (MFB).