University of Toronto

About: University of Toronto is a education organization based out in Toronto, Ontario, Canada. It is known for research contribution in the topics: Population & Health care. The organization has 126067 authors who have published 294940 publications receiving 13536856 citations. The organization is also known as: UToronto & U of T.

Revision of the Physical Activity Readiness Questionnaire (PAR-Q).

Abstract: The original Physical Activity Readiness Questionnaire (PAR-Q) offers a safe preliminary screening of candidates for exercise testing and prescription, but it screens out what seems an excessive proportion of apparently healthy older adults. To reduce unnecessary exclusions, an expert committee established by Fitness Canada has now revised the questionnaire wording. The present study compares responses to the original and the revised PAR-Q questionnaire in 399 men and women attending 40 accredited fitness testing centres across Canada. The number of subjects screened out by the revised test decreased significantly (p < .05), from 68 to 48 of the 399 subjects. The change reflects in part the inclusion of individuals who had made an erroneous positive response to the original question regarding high blood pressure. There is no simple gold standard to provide an objective evaluation of the sensitivity and specificity of either questionnaire format, but the revised wording has apparently had the intended effect of reducing positive responses, particularly to the question regarding an elevation of blood pressure.

The organization of recent and remote memories

Abstract: A fundamental question in memory research is how our brains can form enduring memories. In humans, memories of everyday life depend initially on the medial temporal lobe system, including the hippocampus. As these memories mature, they are thought to become increasingly dependent on other brain regions such as the cortex. Little is understood about how new memories in the hippocampus are transformed into remote memories in cortical networks. However, recent studies have begun to shed light on how remote memories are organized in the cortex, and the molecular and cellular events that underlie their consolidation.

Estimates of optimal vitamin D status

Abstract: Vitamin D has captured attention as an important determinant of bone health, but there is no common definition of optimal vitamin D status. Herein, we address the question: What is the optimal circulating level of 25-hydroxyvitamin D [25(OH)D] for the skeleton? The opinions of the authors on the minimum level of serum 25(OH)D that is optimal for fracture prevention varied between 50 and 80 nmol/l. However, for five of the six authors, the minimum desirable 25(OH)D concentration clusters between 70 and 80 nmol/l. The authors recognize that the average older man and woman will need intakes of at least 20 to 25 mcg (800 to 1,000 IU) per day of vitamin D3 to reach a serum 25(OH)D level of 75 nmol/l. Based on the available evidence, we believe that if older men and women maintain serum levels of 25(OH)D that are higher than the consensus median threshold of 75 nmol/l, they will be at lower risk of fracture.

Erlotinib in lung cancer - molecular and clinical predictors of outcome.

Abstract: Background A clinical trial that compared erlotinib with a placebo for non–small-cell lung cancer demonstrated a survival benefit for erlotinib. We used tumor-biopsy samples from participants in this trial to investigate whether responsiveness to erlotinib and its impact on survival were associated with expression by the tumor of epidermal growth factor receptor (EGFR) and EGFR gene amplification and mutations. Methods EGFR expression was evaluated immunohistochemically in non–small-cell lung cancer specimens from 325 of 731 patients in the trial; 197 samples were analyzed for EGFR mutations; and 221 samples were analyzed for the number of EGFR genes. Results In univariate analyses, survival was longer in the erlotinib group than in the placebo group when EGFR was expressed (hazard ratio for death, 0.68; P=0.02) or there was a high number of copies of EGFR (hazard ratio, 0.44; P=0.008). In multivariate analyses, adenocarcinoma (P=0.01), never having smoked (P<0.001), and expression of EGFR (P=0.03) were a...