University of Saskatchewan

About: University of Saskatchewan is a education organization based out in Saskatoon, Saskatchewan, Canada. It is known for research contribution in the topics: Population & Health care. The organization has 25021 authors who have published 52579 publications receiving 1483049 citations. The organization is also known as: USask.

MELAS: Clinical features, biochemistry, and molecular genetics

Abstract: We studied 23 patients with clinically defined mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes (MELAS), 25 oligosymptomatic or asymptomatic maternal relatives, and 50 mitochondrial disease control subjects for the presence of a previously reported heteroplasmic point mutation at nt 3,243 in the transfer RNA(Leu(UUR)) gene of mitochondrial DNA. We found a high concordance between clinical diagnosis of MELAS and transfer RNA(Leu(UUR)) mutation, which was present in 21 of the 23 patients with MELAS, all 11 oligosymptomatic and 12 of 14 asymptomatic relatives, but in only five of 50 patients without MELAS. The proportion of mutant genomes in muscle ranged from 56 to 95% and was significantly higher in the patients with MELAS than in their oligosymptomatic or asymptomatic relatives. In subjects in whom both muscle and blood were studied, the percentage of mutations was significantly lower in blood and was not detected in three of 12 asymptomatic relatives. The activities of complexes I + III, II + III, and IV were decreased in muscle biopsies harboring the mutation, but there was no clear correlation between percentage of mutant mitochondrial DNAs and severity of the biochemical defect.

Solid acid catalyzed biodiesel production from waste cooking oil

Abstract: Various solid acid catalysts were evaluated for the production of biodiesel from low quality oil such as waste cooking oil (WCO) containing 15 wt.% free fatty acids. The zinc stearate immobilized on silica gel (ZS/Si) was the most effective catalyst in simultaneously catalyzing the transesterification of triglycerides and esterification of free fatty acid (FFA) present in WCO to methyl esters. The optimization of reaction parameters with the most active ZS/Si catalyst showed that at 200 °C, 1:18 oil to alcohol molar ratio and 3 wt.% catalysts loading, a maximum ester yield of 98 wt.% could be obtained. The catalysts were recycled and reused many times without any loss in activity.

Comparative effects of inhaled salbutamol, sodium cromoglycate, and beclomethasone dipropionate on allergen-induced early asthmatic responses, late asthmatic responses, and increased bronchial responsiveness to histamine

Abstract: Single-dose salbutamol (200 micrograms), beclomethasone dipropionate (200 micrograms), and sodium cromoglycate (SCG) (10 mg) administered by inhalation 10 minutes before allergen challenge were examined with regard to inhibition of allergen-induced early (EAR) and late (LAR) asthmatic responses and allergen-induced increase in bronchial responsiveness to inhaled histamine. Ten atopic subjects with asthma participated in a blinded, crossover, placebo-controlled trial. The EAR was inhibited by salbutamol and SCG but not by beclomethasone dipropionate or placebo (p less than 0.01). The LAR (p less than 0.01) and the allergen-induced increased bronchial responsiveness to histamine 7 hours (p less than 0.01) and 30 hours (p less than 0.05 and p less than 0.01 for various comparisons) were inhibited by SCG and beclomethasone diproprionate but not by salbutamol or placebo. The allergen-induced LAR and associated increased responsiveness are now believed to be more important clinically than the EAR. The clinical relevance of these results is to stress the importance of the prophylactic nonbronchodilator drugs (SCG and steroids) and the potential inadequacy of bronchodilators used alone in the treatment of both perennial and seasonal allergic asthma.

The Development of a New Instrument: "Views on Science- Technology-Society" (VOSTS)

Abstract: Educators who plan science lessons, who develop science curricula, or who evaluate learning, often wonder about students' preconceptions of the material to be taught. Until now, attention has mainly focused on traditional science content (Driver, 1988; West and Pines, 1985). However, content related to the nature of science (for example, science's epistemology and its social context) is receiving increased attention because of interest in teaching science through a science-tech-nology-society (STS) approach or teaching science in concert with the history and philosophy of science (Bybee, 1987; Hodson, 1988; Posner and Strike, 1989; Gruen-der and Tobin, 1991); What are high school students' preconceptions concerning the epistemology and sociology of science? This question is addressed in two related articles that stem from the same research study. This first article describes the development of a new research instrument that monitors students' views on a broad range of STS topics,