Université de Saint-Boniface

The role of ATP-regulated K+ channels in protecting the myocardium against ischemia/reperfusion damage was explored using glibenclamide and pinacidil to block and activate the channels, respectively. Electrical and mechanical activity of arterially perfused guinea pig right ventricular walls was recorded simultaneously via an intracellular microelectrode and a force transducer. The preparations were subjected to either 1) 20 minutes of no-flow ischemia with or without glibenclamide (1 and 10 microM) followed by reperfusion, or 2) 30 minutes of no-flow ischemia with or without pinacidil (1 and 10 microM) followed by reperfusion. No-flow ischemia for 20 minutes produced changes in electrical and mechanical activity that were completely reversed on reperfusion; resting membrane potential declined by 13 +/- 1.2 mV, action potential duration at 90% repolarization (APD90) decreased by 62%, and developed tension fell by greater than 95%, but resting tension did not change significantly. Glibenclamide (10 microM) had no effect on activity during normal perfusion, but during ischemia, resting membrane potential fell slightly further (17 +/- 1.8 mV) and APD90 declined by only 24%. Developed tension declined more slowly and to a lesser extent, but resting tension rose significantly between 10 and 20 minutes of ischemia. Reperfusion of glibenclamide-treated tissues elicited arrhythmias (extrasystoles and tachycardia), and the preparations failed to recover mechanical function. Glibenclamide at 1 microM produced qualitatively similar effects, albeit less severe. After 30 minutes of no-flow ischemia in untreated tissues, resting tension increased by approximately 130% during the no-flow period. Reperfusion caused arrhythmias (extrasystoles, tachyarrhythmias, and fibrillation) and failed to restore resting or developed tension to preischemic levels. Pinacidil at 1 microM did not affect electrical or contractile function, but at 10 microM it had a negative inotropic effect, decreasing APD90 and developed tension by 5% and 18%, respectively. Both concentrations of the drug caused a faster and greater decline in APD90 during the no-flow period. Resting tension did not change during 30 minutes of no-flow ischemia in the presence of pinacidil, and reperfusion led to 85% and complete recovery of electrical and mechanical activity at 1 and 10 microM, respectively. The data indicate that glibenclamide enhances whereas pinacidil reduces myocardial damage caused by ischemia/reperfusion. The results are consistent with the hypothesis that activation of ATP-regulated K+ channels during ischemia is an important adaptive mechanism for protecting the myocardium when blood flow to the tissue is compromised.

Abstract The published literature on writing to learn in science was reviewed in order to develop a conceptual framework for readers of this special issue and an agenda for future research. Professional journals, books, ERIC documents, and doctoral dissertations were consulted in this review process. Research on writing to learn has been hindered because studies have not always been well designed or clearly reported, and few have been conducted in authentic classroom environments. Furthermore, the links between writing to learn and conceptual change, and writing to learn and critical thinking have not received sufficient attention. Carefully designed studies, both qualitative and quantitative, are still required to provide data from a variety of perspectives. Because the reported studies at the college level outnumber those at other levels, research is still required to generalize the findings across a variety of science classrooms and to elucidate principles for guiding effective teacher use of writing‐to‐learn strategies.

This study investigated the role of talk and writing on learning science. The purpose was to explore the effect of talk, writing, and talk and writing on the learning and retention of simple and integrated knowledge, and to describe the mechanisms by which talk and writing mediate these processes. Forty-three students were randomly assigned to four groups, all stratified for gender and ability. At intervals during an instructional unit, three treatment groups received problem tasks that involved constructing scientific explanations for real-world applications of ecological concepts. A control group received simpler descriptive tasks based on similar content. Students in the talk-only treatment group (T) discussed the problem tasks in small peer groups. Students in the writing-only treatment group (W) individually wrote responses for each of the tasks, but without first talking to other students. Students in the combined talk and writing treatment group (TW) discussed the problems in groups prior to individually writing their explanations. Dependent variables included simple, integrated, and total knowledge scores based on multiple-choice tests, essay questions, and concept maps obtained at three timepoints during the study: a pretest; an immediate posttest; and a delayed posttest. Records of student talk and writing were also analyzed to describe the mechanisms involved. The findings suggest that talk is important for sharing, clarifying, and distributing knowledge among peers, while asking questions, hypothesizing, explaining, and formulating ideas together are all important mechanisms during peer discussions. Analytical writing is an important tool for transforming rudimentary ideas into knowledge that is more coherent and structured. Furthermore, talk combined with writing appears to enhance the retention of science learning over time. Moreover, gender and ability may be important mediating variables that determine the effectiveness of talk and writing for enhancing learning. © 2000 John Wiley & Sons, Inc. Sci Ed 84:566–593, 2000.

This study investigated the role of talk and writing on learning science. The purpose was to explore the effect of talk, writing, and talk and writing on the learning and retention of simple and integrated knowledge, and to describe the mechanisms by which talk and writing mediate these processes. Forty-three students were randomly assigned to four groups, all stratified for gender and ability. At intervals during an instructional unit, three treatment groups received problem tasks that involved constructing scientific explanations for real-world applications of ecological concepts. A control group received simpler descriptive tasks based on similar content. Students in the talk-only treatment group (T) discussed the problem tasks in small peer groups. Students in the writing-only treatment group (W) individually wrote responses for each of the tasks, but without first talking to other students. Students in the combined talk and writing treatment group (TW) discussed the problems in groups prior to individually writing their explanations. Dependent variables included simple, integrated, and total knowledge scores based on multiple-choice tests, essay questions, and concept maps obtained at three timepoints during the study: a pretest; an immediate posttest; and a delayed posttest. Records of student talk and writing were also analyzed to describe the mechanisms involved. The findings suggest that talk is important for sharing, clarifying, and distributing knowledge among peers, while asking questions, hypothesizing, explaining, and formulating ideas together are all important mechanisms during peer discussions. Analytical writing is an important tool for transforming rudimentary ideas into knowledge that is more coherent and structured. Furthermore, talk combined with writing appears to enhance the retention of science learning over time. Moreover, gender and ability may be important mediating variables that determine the effectiveness of talk and writing for enhancing learning. © 2000 John Wiley & Sons, Inc. Sci Ed 84:566–593, 2000.

PURPOSE: Whereas intussusception is relatively common in children, it is clinically rare in adults. The condition is usually secondary to a definable lesion. This study was designed to review adult intussusception, including presentation, diagnosis, and optimal treatment. METHODS: A retrospective review of 22 cases of intussusception occurring in individuals older than aged 18 years encountered at two university-affiliated hospitals in Winnipeg between 1989 and 2000. The 22 cases were divided to benign and malignant enteric, ileocolic, colonic lesions respectively. The diagnosis and treatment of each case were reviewed. RESULTS: There were 22 cases of adult intussusception. Mean age was 57.1 years. Abdominal pain, nausea, and vomiting were the commonest symptoms. There were 14 enteric, 2 ileocolic, and 6 colonic intussusceptions. Eighty-six percent of adult intussusception was associated with a definable lesion. Twenty-nine percent of enteric lesions were malignant. All ileocolic lesions were malignant. Of colonic lesions, 33 percent were malignant and 67 percent were benign. All cases required surgical interventions except one. CONCLUSIONS: Adult intussusception is a rare entity and requires a high index of suspicion. Our review supports that small-bowel intussusception should be reduced before resection if the underlying etiology is suspected to be benign or if the resection required without reduction is deemed to be massive. Large bowel should generally be resected without reduction because pathology is mostly malignant.

INTRODUCTION: The risks to patient safety and quality of care faced by members of linguistic minority groups have been well-documented. However, little research has focused on the experience of official language minorities in Canada. METHODS: This multiple method study (online and paper-based surveys combined with semi-structured individual interviews with patients and interpreters-health navigators) explored the experience of minority Francophones living in 4 Canadian provinces. RESULTS: Patients and interpreters-navigators described experiences where language barriers contributed to poorer patient assessment, misdiagnosis and/or delayed treatment, incomplete understanding of patient condition and prescribed treatment, and impaired confidence in services received. Reliance on Google Translate and ad hoc, untrained interpreters are commonly reported, in spite of evidence highlighting the risks associated with such practice. CONCLUSION: Increased awareness that the risks of language barriers apply to official language minorities is essential.

Successful treatment of cancer by boron neutron capture therapy (BNCT) requires the selective delivery of (10)B to constituent cells within a tumor. The expression of the folate receptor is amplified in a variety of human tumors and potentially might serve as a molecular target for BNCT. In the present study we have investigated the possibility of targeting the folate receptor on cancer cells using folic acid conjugates of boronated poly(ethylene glycol) (PEG) containing 3rd generation polyamidoamine dendrimers to obtain (10)B concentrations necessary for BNCT by reducing the uptake of these conjugates by the reticuloendothelial system. First we covalently attached 12-15 decaborate clusters to 3rd generation polyamidoamine dendrimers. Varying quantities of PEG units with varying chain lengths were then linked to these boronated dendrimers to reduce hepatic uptake. Among all prepared combinations, boronated dendrimers with 1-1.5 PEG(2000) units exhibited the lowest hepatic uptake in C57BL/6 mice (7.2-7.7% injected dose (ID)/g liver). Thus, two folate receptor-targeted boronated 3rd generation polyamidoamine dendrimers were prepared, one containing approximately 15 decaborate clusters and approximately 1 PEG(2000) unit with folic acid attached to the distal end, the other containing approximately 13 decaborate clusters, approximately 1 PEG(2000) unit, and approximately 1 PEG(800) unit with folic acid attached to the distal end. In vitro studies using folate receptor (+) KB cells demonstrated receptor-dependent uptake of the latter conjugate. Biodistribution studies with this conjugate in C57BL/6 mice bearing folate receptor (+) murine 24JK-FBP sarcomas resulted in selective tumor uptake (6.0% ID/g tumor), but also high hepatic (38.8% ID/g) and renal (62.8% ID/g) uptake, indicating that attachment of a second PEG unit and/or folic acid may adversely affect the pharmacodynamics of this conjugate.

BACKGROUND: Healthy aging (HA) is a contemporary challenge for population health worldwide. Electronic health (e-Health) interventions have the potential to support empowerment and education of adults aged 50 and over. OBJECTIVES: To summarize evidence on the effectiveness of e-Health interventions on HA and explore how specific e-Health interventions and their characteristics effectively impact HA. METHODS: A systematic review was conducted based on the Cochrane Collaboration methods including any experimental study design published in French, Dutch, Spanish, and English from 2000 to 2018. RESULTS: Fourteen studies comparing various e-Health interventions to multiple components controls were included. The target population, type of interventions, and outcomes measured were very heterogeneous across studies; thus, a meta-analysis was not possible. However, effect estimates indicate that e-Health interventions could improve physical activity. Positive effects were also found for other healthy behaviors (e.g., healthy eating), psychological outcomes (e.g., memory), and clinical parameters (e.g., blood pressure). Given the low certainty of the evidence related to most outcomes, these results should be interpreted cautiously. CONCLUSIONS: This systematic review found limited evidence supporting the effectiveness of e-Health interventions, although the majority of studies show positive effects of these interventions for improving physical activity in older adults. Thus, better quality evidence is needed regarding the effects of e-Health on the physiological, psychological, and social dimensions of HA. SYSTEMATIC REVIEW REGISTRATION: The review protocol was registered in PROSPERO (registration number: CRD42016033163).

Polyhexamethylene guanidine hydrochloride (PHMGH), an antimicrobial biocide of the guanidine family, was tested for efficacy against quality-control strains of Staphylococcus aureus, Pseudomonas aeruginosa, Salmonella choleraesuis, meticillin-resistant S. aureus (MRSA) and Escherichia coli. Bactericidal activity against S. aureus, P. aeruginosa and Salmonella choleraesuis was determined using the official methods of analysis of the Association of Official Analytical Chemists, with modifications as recommended by the Canadian General Standards Board. For MRSA and E. coli, the MIC and minimal bactericidal concentration were determined using the broth dilution technique. The experiments were carried out at 20 degrees C under a range of conditions including varying PHMGH concentration (0.001-0.1 %), contact time (0.5-10 min) and water type (distilled, tap and hard water). The phenol coefficient values determined with S. aureus, Salmonella choleraesuis and P. aeruginosa were 7.5, 6.1 and 5, respectively. No matter what type of water was used to make the dilutions, PHMGH killed MRSA and E. coli at concentrations as low as 0.04 and 0.005 % (w/v), respectively, within 1.5 min. The mode of action of PHMGH was elucidated by transmission electron microscopy: the cell envelope was broken, resulting in cell content leakage into the medium. The ultimate aim of this study was to show that PHMGH can be used as an odourless, colourless, non-corrosive and harmless disinfectant for hospital and household facilities.

We previously demonstrated that ATP-sensitive K+ channels (KATP) protect the guinea pig myocardium against ischemia-reperfusion injury (Cole et al., Circ. Res. 69: 571-581, 1991), but the cellular alterations leading to ischemic injury affected by KATP remain to be defined. This study investigates the relationship between activation of KATP and preservation of high-energy phosphates during global no-flow ischemia in arterially perfused guinea pig right ventricular walls. Electrical and mechanical activity were recorded via intracellular microelectrodes and a force transducer. Glibenclamide (10 and 50 microM) and pinacidil (10 microM) were used to modulate KATP. ATP and creatine phosphate (CP) levels were determined at the end of no-flow ischemia by enzymatic analysis. Preparations were subjected to 1) 20 min no-flow +/- glibenclamide (10 or 50 microM), 2) 30 min no-flow +/- pinacidil (10 microM) or pinacidil (10 microM) and glibenclamide (50 microM), or 3) 40 or 50 min of control perfusion before rapid freezing in liquid nitrogen. Pinacidil (10 microM) enhanced ischemic shortening of action potential duration (APD) and early contractile failure, prevented ischemic contracture, and inhibited high-energy phosphate depletion during ischemia. Glibenclamide (50 microM) inhibited the effects of pinacidil (10 microM) on electromechanical function and preservation of ATP and CP. Glibenclamide (10 microM) alone inhibited the early decline in APD and produced earlier ischemic contracture but did not enhance ATP or CP depletion compared with untreated tissues during 20 min of no-flow. Glibenclamide (50 microM) produced a greater inhibition of APD shortening in early ischemia, further decreased the latency to ischemic contracture, and caused enhanced ischemic depletion of ATP. The data indicate the changes in electrical activity induced by KATP indirectly preserve high-energy phosphates and reduce injury associated with ischemia. However, the data also suggest the possible presence of additional mechanisms for cardioprotection by KATP.

BACKGROUND: Emerging evidence that meaningful relationships with knowledge users are a key predictor of research use has led to promotion of partnership approaches to health research. However, little is known about health system experiences of collaborations with university-based researchers, particularly with research partnerships in the area of health system design and health service organization. The purpose of the study was to explore the experience and perspectives of senior health managers in health service organizations, with health organization-university research partnerships. METHODS: In-depth, semi-structured interviews (n = 25) were conducted with senior health personnel across Canada to explore their perspectives on health system research; experiences with health organization-university research partnerships; challenges to partnership research; and suggested actions for improving engagement with knowledge users and promoting research utilization. Participants, recruited from organizations with regional responsibilities, were responsible for system-wide planning and support functions. RESULTS: Research is often experienced as unhelpful or irrelevant to decision-making by many within the system. Research, quality improvement (QI) and evaluation are often viewed as separate activities and coordinated by different responsibility areas. Perspectives of senior managers on barriers to partnership differed from those identified in the literature: organizational stress and restructuring, and limitations in readiness of researchers to work in the fast-paced healthcare environment, were identified as major barriers. Although the need for strong executive leadership was emphasized, "multi-system action" is needed for effective partnerships. CONCLUSION: Common approaches to research and knowledge translation are often not appropriate for addressing issues of health service design and health services organization. Nor is the research community providing expertise to many important activities that the healthcare system is taking to improve health services. A radical rethinking of how we prepare health service researchers; position research within the health system; and fund research activities and infrastructure is needed if the potential benefits of research are to be achieved. Lack of response to health system needs may contribute to research and 'evidence-informed' practice being further marginalized from healthcare operations. Interventions to address barriers must respond to the perspectives and experience of health leadership.

Abstract The study investigated achievement status as a factor determining the use of language‐based activities for learning science. A total of 154 eighth‐grade students were randomly assigned to four groups, all stratified for gender and achievement level. The treatments involved various combinations of talk and writing, and descriptive and explanatory tasks. The dependent measures included scores on multiple choice tests obtained at three times during the study. Records of student talk and writing were also analyzed to identify patterns of differences between groups of achievers. The findings suggested that low achievers complete more problems, and develop better understanding and comprehension of ecology concepts when they have engaged in peer discussions of explanatory tasks. In comparison, high achievers benefit more from writing than talking, and writing explanations enhances comprehension more than restricted writing activities. © 2004 Wiley Periodicals, Inc. Sci Ed 88: 420–442, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/.sce10114

BACKGROUND: Reduction of the stigma of mental illness is an international priority; arts- and contact-based approaches represent a promising mode of intervention. This project was designed to explore the impact of a one-woman theatrical performance on attitudes towards bipolar disorder (BD) on people with BD and healthcare providers. METHODS: A playwright and actress who lives with BD developed a stage performance - 'That's Just Crazy Talk' - targeting stigmatizing attitudes towards BD. Prospective, longitudinal and sequential mixed methods were used to assess the impact of the performance on people with BD (n = 80) and healthcare providers (n = 84). Qualitative interviews were conducted with 33 participants (14 people with BD and 19 healthcare providers). RESULTS AND DISCUSSION: Quantitatively, healthcare providers showed significantly improved attitudes immediately post-performance, but this change was not maintained over time; people with BD showed little quantitative change. Qualitatively, both people with BD and BD healthcare providers showed enduring and broadly positive changes. A theatrical presentation designed to reduce stigma produced immediate impact on healthcare providers quantitatively and significant qualitative impact on people with BD and healthcare providers. Additionally, the utility of using mixed-method approaches in mental health research was demonstrated.

Background Limited data exist on clinical valve thrombosis after transcatheter aortic valve-in-valve (ViV) implantation. Our objective was to determine the incidence, timing, clinical characteristics, and treatment outcomes of patients diagnosed with clinical ViV thrombosis. Methods and Results Centers participating in the Valve-in-Valve International Data Registry were surveyed for thrombosis cases, and clinical valve thrombosis was defined based on a combination of the presence of new valve dysfunction and an imaging evidence of leaflet thrombosis. Three hundred ViV implantations were included. The surgical valve was stented in 86.3% and stentless in 13.7% of cases; and the transcatheter heart valve was self-expanding in 50%, balloon-expandable in 49%, and mechanically expanding in 1.0%. The incidence of clinical valve thrombosis was 7.6% (n=23), diagnosed at a median time of 101 days (interquartile range, 21-226) after the procedure. Fifteen patients (65%) presented with worsening symptoms and 21 (91%) with transvalvular mean gradient elevation. The mean gradient at the time of diagnosis (median 39 mm Hg; interquartile range, 30-44) was significantly higher than immediately post-ViV (13 mm Hg; interquartile range, 8-20.5; P<0.001) and was significantly reduced after oral anticoagulation therapy (17.5 mm Hg; interquartile range, 11-20.5; P<0.001). There were no deaths or strokes related to valve thrombosis. Factors associated with valve thrombosis were oral anticoagulation (odds ratio [95% confidence limits]: 0.067 [0.008-0.543], P=0.011), surgical valve true internal diameter indexed to body surface area (0.537 [0.331-0.873], P=0.012), and Mosaic or Hancock II stented porcine bioprostheses (4.01 [1.287-12.485], P=0.017). Conclusions Clinical valve thrombosis after transcatheter aortic ViV implantation is common, especially in patients not on oral anticoagulation. Although aortic ViV is commonly associated with elevated gradients, valve thrombosis should be ruled out if gradients increase compared with early postprocedural values. A higher incidence was observed after treatment of certain stented porcine surgical valve types, suggesting a specific adjustment of the adjunctive antithrombotic therapy in this subset of ViV patients.

BACKGROUND: The PRISMA Model is an innovative coordination-type integrated-service-delivery (ISD) network designed to manage and better match resources to the complex and evolving needs of elders. The goal of this study was to examine the impact of this ISD network on unmet needs among disabled older persons living in the community. METHODS: Using data from the PRISMA study, we compared unmet needs of elders living in the community in areas with or without an ISD network. Disabilities and unmet needs were assessed with the Functional Autonomy Measurement System (SMAF). We used growth-curve analysis to examine changes in unmet needs over time and the variables associated with initial status and change. Sociodemographic characteristics, level of disability, self-perceived health status, cognitive functioning, level of empowerment, and the hours of care received were investigated as covariates. Lastly, we report the prevalence of needs and unmet needs for 29 activities in both areas at the end of the study. RESULTS: On average, participants were 83 years old; 62% were women. They had a moderate level of disability and mild cognitive problems. On average, they received 2.07 hours/day (SD = 1.08) of disability-related care, mostly provided by family. The findings from growth-curve analysis suggest that elders living in the area where ISD was implemented and those with higher levels of disability experience better fulfillment of their needs over time. Besides the area, being a woman, living alone, having a higher level of disability, more cognitive impairments, and a lower level of empowerment were linked to initial unmet needs (r2 = 0.25; p < 0.001). At the end of the study, 35% (95% CI: 31% to 40%) of elders with needs living in the ISD area had at least one unmet need, compared to 67% (95% CI: 62% to 71%) in the other area. In general, unmet needs were highest for bathing, grooming, urinary incontinence, walking outside, seeing, hearing, preparing meals, and taking medications. CONCLUSIONS: In spite of more than 30 years of home-care services in the province of Quebec, disabled older adults living in the community still have unmet needs. ISD networks such as the PRISMA Model, however, appear to offer an effective response to the long-term-care needs of the elderly.

plant, are synthetic analogues, or occur endogenously. Although cannabinoids interact mostly at the level of the currently recognized cannabinoid receptors, they might have cross reactivity, such as at opioid receptors. Patients with malignant disease represent a cohort within health care that have some of the greatest unmet needs despite the availability of a plethora of guideline-driven disease-modulating treatments and pain and symptom management options. Cannabinoid therapies are varied and versatile, and can be offered as pharmaceuticals (nabilone, dronabinol, and nabiximols), dried botanical material, and edible organic oils infused with cannabis extracts. Cannabinoid therapy regimens can be creative, involving combinations of all of the aforementioned modalities. Patients with malignant disease, at all points of their disease trajectory, could be candidates for cannabinoid therapies whether as monotherapies or as adjuvants. The most studied and established roles for cannabinoid therapies include pain, chemotherapy-induced nausea and vomiting, and anorexia. Moreover, given their breadth of activity, cannabinoids could be used to concurrently optimize the management of multiple symptoms, thereby reducing overall polypharmacy. The use of cannabinoid therapies could be effective in improving quality of life and possibly modifying malignancy by virtue of direct effects and in improving compliance or adherence with disease-modulating treatments such as chemotherapy and radiation therapy.

While there is strong international evidence that language barriers present obstacles to healthcare access, quality and safety, little research has been conducted on the experience of official language minorities in Canada. This multiple method research used on-line and paper-based surveys, combined with semi-structured individual interviews to explore the experience with access to care of Francophone minorities living in four Canadian provinces. The majority of Francophones surveyed reported limited access to French language services and described an environment where low importance is given to addressing language barriers within the health system. Even when services are available, the lack of services in French sometimes results in avoidance of care. Results confirm that many Francophones face similar barriers to care as other language minorities in Canada. Strategies to improve access for official language minorities are discussed.

Oxygen-derived free radicals (O-Rs) are thought to induce alterations in cardiac electrical activity; however, the underlying membrane ionic currents affected by O-Rs and the mechanisms by which O-Rs induce their effects on ion channels in the heart are not well defined. In this study, we investigated the time-dependent changes in resting membrane potential and action potential configuration and changes in steady-state membrane currents in guinea pig ventricular myocytes after intracellular application of an O-R-generating system. O-Rs were generated from the combination of dihydroxyfumaric acid (3 mM) and FeCl3:ADP (0.05:0.5 mM) added to the pipette solution that was used to record membrane potential and currents via the whole-cell variant of the patch-clamp technique. Intracellular exposure of myocytes to the O-R-generating solution induced three stages of changes: 1) an early depolarization (5-10 mV) and an increase in action potential duration accompanied by a decrease in resting inward rectifying K+ current conductance, 2) delayed afterdepolarizations and triggered activity caused by the activation of transient inward current mediated by Na(+)-Ca2+ exchange, with failure to repolarize and sustained depolarization between -35 and -20 mV, reflecting the stimulation of nonselective cation current, and 3) a late stage of marked decline in action potential duration, hyperpolarization, and loss of excitability accompanied by activation of the outward current through ATP-sensitive K+ channels. These alterations in electrical activity and membrane currents could be prevented by pretreatment with N-(2-mercaptopropionyl)glycine (500 microM), a scavenger of hydroxyl free radicals. The alterations associated with stages 1 and 2 but not stage 3 were completely abolished on intracellular Ca2+ chelation (5 mM EGTA in the pipette solution) or disruption of sarcoplasmic reticulum Ca2+ handling with ryanodine (10 microM). This study shows that intracellular O-R stress causes specific alterations in membrane ionic currents, leading to changes in resting membrane potential and action potential configuration. Moreover, the data indicate that an elevation in intracellular Ca2+ due to abnormal Ca2+ handling by the sarcoplasmic reticulum is a cause of some of the alterations in membrane currents during O-R stress.

Education is paramount when trying to enable a change in values and attitudes towards sustainability. Higher education in faculties of education plays an important role in working toward this change because of its impact on future and practicing teachers in the school systems. This study inquires into the current role of education for sustainable development (ESD) in undergraduate and graduate teacher education programs at Canadian universities, with a particular focus on promising practices and initiatives toward a reorientation of teacher education for sustainability. A qualitative case study approach was used identifying promising initiatives as well as challenges and enablers of reorienting teacher education toward sustainability at four Canadian universities. The discussion of results is framed by how identified initiatives relate to the development of core ESD competences for educators as established by UNECE (2012). The results of the study suggest the importance of experiential, inter-disciplinary and inter-institutional learning, of problem-based learning around real-life issues with community and the natural environment, and of building partnerships with colleagues, students, and community organizations.

Abstract Manual detection and quantitation of apneas from an all-night polysomnogram is very time-consuming. Because SaO2 changes with virtually every apnea event, we reasoned that by identifying cyclical SaO2 changes, we could calculate (1) an apnea-hypopnea index that would correlate very well with the manually derived apnea-hypopnea index, and (2) the duration of apnea-hypopnea events. We developed a computer algorithm to scan and detect dips in SaO2 data digitally stored as a time series by computer throughout overnight studies. Desaturations detected by computer were compared with the events detected manually in 9 all-night polysomnograms from 6 patients with typical obstructive sleep apnea. Events detected by one method but not the other were subsequently verified to determine the overall number of apnea-hypopnea events present and to determine false positive and false negative rates for the 2 methods of detection. The total number of apneas was 4,008. Both methods agreed on 3,639 of them. Of 77 manually recorded apneas not detected by computer, 24 were subsequently discounted (manual false positives, 24 of 4,007 = 0.6%) and 53 confirmed (computer false negatives, 1.32%). Of 358 events not detected manually, 316 were confirmed (manual false negatives, 7.9%) and 42 discounted (computer false positives, 1.1%). Using the final manual scoring as the reference, the computer program detected apneas with a sensitivity of 97.9%, and the predictive value of a computer-detected event was 90.8%. for event duration, a regression was performed on 3,623 matched apneas-hypopnea events, giving a coefficient of r = 0.9431, p &amp;lt; 10−6. We conclude that computer-based analysis of continuous SaO2 will detect apneas and hypopneas with a very high sensitivity and a very low false positive and false negative rate, and thus can be used to calculate event number and duration.