How Societal Forces of Change Are Transforming Youth Physical Activity Promotion in North America

BACKGROUND

Climate change, increasing recognition of institutionalized discrimination, and the COVID-19 pandemic are large-scale, societal events (ie, forces of change) that affect the timing, settings, and modes of youth physical activity. Despite the impact that forces of change have on youth physical activity and physical activity environments, few studies consider how they affect physical activity promotion.

METHODS

The authors use 2 established frameworks, the ecological model of physical activity and the youth physical activity timing, how, and setting framework, to highlight changes in physical activity patterns of youth in North America that have resulted from contemporary forces of change.

RESULTS

North American countries-Canada, Mexico, and the United States-have faced similar but contextually different challenges for promoting physical activity in response to climate change, increasing recognition of institutionalized discrimination, and the COVID-19 pandemic. Innovative applications of implementation science, digital health technologies, and community-based participatory research methodologies may be practical for increasing and sustaining youth physical activity in response to these forces of change.

CONCLUSIONS

Thoughtful synthesis of existing physical activity frameworks can help to guide the design and evaluation of new and existing physical activity initiatives. Researchers, practitioners, and policymakers are encouraged to carefully consider the intended and unintended consequences of actions designed to respond to forces of change.

Associations between Screen-Based Activities, Physical Activity, and Dietary Habits in Mexican Schoolchildren

Screen-based activities are associated with increased risk of obesity and contribute to physical inactivity and poor dietary habits. The primary aim of this study was to examine the associations among screen-based activities, physical activity, and dietary habits in school-aged children in Guadalajara, Puerto Vallarta, and Mexico City, Mexico. The secondary aim was to examine these associations across sex. The School Physical Activity and Nutrition survey was used to assess screen-based activities (TV watching, video game use, computer use), physical activity, and dietary habits. Organized activity/sports participation, unhealthy dietary habits, and household income were correlated with screen-based activities. While TV watching was associated with decreased participation in organized activity/sports participation, computer and video game use was associated with increased organized activity/sports participation. Boys engaged in more TV watching and video game use compared to girls. All screen-based activities were associated with age among boys; whereas video game and computer use were associated with higher income among girls. These findings suggest a need for sex- and age-specific strategies that acknowledge the differential use of screen-based activities across sex and age. Future research should continue to identify underlying correlates linking screen-based activities with health behaviors to inform strategies to reduce screen-time in Mexican children.

Indigenous Youth Development through Sport and Physical Activity: Sharing Voices, Stories, and Experiences

Recent research has highlighted the cognitive, physical, emotional, and spiritual benefits of sport and physical activity participation for Indigenous youth (McHugh, Coppola, & Sinclair, 2013; Hanna, 2009; Lavallée, 2007). Despite the importance of Indigenous peoples participating in sport and physical activity (e.g., Forsyth & Giles, 2013), the meaning of youth development in this context is not well understood. The purpose of this research was to understand Indigenous youth development within the context of sport and physical activity through the voices, stories and experiences of Indigenous youth. Participants were 99 Indigenous youth (52 males and 47 females) between the ages of 15 and 25 years who took part in one of 13 sharing circles. Each of the sharing circles was facilitated by a trained Indigenous youth with guidance from an Elder/Traditional person. A Two-Eyed Seeing approach (Bartlett, Marshall, & Marshall, 2012) was used to analyze the sharing circle discussions. This analytical process involved an initial inductive thematic analysis of the transcribed verbatim data followed by an Indigenous symbolic visual analysis of emerging themes using the Medicine Circle. Results revealed that involvement in sport and physical activity impacted Indigenous youth physically, cognitively, and emotionally. The spiritual impact was not as evident. Findings from the research will inform the development of a measure of Indigenous youth development within sport and physical activity settings.  

Incrementing the Frequency of Dynamic Strain on SMC-Cellularised Collagen-Based Scaffolds Affects Extracellular Matrix Remodeling and Mechanical Properties

Notwithstanding the efforts injected in vascular tissue engineering in the past 30 years, the clinical translation of engineered artery constructs is far from being successful. One common approach to improve artery regeneration is the use of cyclic mechanical stimuli to guide cellular remodeling. However, there is a lack of information on the effect of cyclic strain on cells within a 3D environment. To this end, this work explored the effect of gradual increase in stimulation frequency on the response of human umbilical artery smooth muscle cells (HUASMCs) embedded in a 3D collagen matrix. The results demonstrate that, with an applied strain of 5%, the gradual increase of frequency from 0.1 to 1 Hz improved collagen remodeling by HUASMCs compared to samples constantly stimulated at 1 Hz. The expression of collagen, elastin and matrix metalloproteinase-2 (MMP-2) genes was similar at 7 days for gradual and 1 Hz samples which showed lower amounts than static counterparts. Interestingly the mechanical properties of the constructs, specifically the amplitude of the time constants and the elastic equilibrium modulus, were enhanced by gradual increase of frequency. Taken together, these results show an increase in collagen remodeling by the HUASMCs overtime under incremental cyclic mechanical strain. This work suggests that only the in-depth investigation of the effects of stimulation parameters on the behavior of vSMC under cyclic strain in a 3D environment could lead to the design of optimized control strategies for enhanced vascular tissue generation and maturation in bioreactors.

Validation of reference genes for real-time PCR of cord blood mononuclear cells, differentiating endothelial progenitor cells, and mature endothelial cells

In the last ten years, endothelial progenitor cells (EPCs) have gained interest as an attractive cell population in regenerative medicine for vascular applications. This population is defined as the precursor of endothelial mature cells (ECs) through a process of differentiation. To our knowledge, no single marker can be used to discriminate them from mature ECs. To effectively study their differentiation kinetics, gene expression must be assessed. Quantitative real-time PCR (RT-qPCR) is widely used to analyze gene expression. To minimize the impact of variances from RT-qPCR, a rigorous selection of reference genes must be performed prior to any experiments due to variations in experimental conditions. In this study, CD34+ mononuclear cells were extracted from human cord blood and differentiated into EPCs after seeding for a maximum period of 21 days. To choose the best combinations of reference genes, we compared the results of EPCs, CD34+ mononuclear cells, and mature endothelial cells to ensure that the differentiation kinetics did not affect the expression of our selected reference genes. The expression levels of seven genes, namely, YWHAZ, GAPDH, HPRT1, RPLP0, UBC, B2M, and TBP were thus compared. The algorithms geNorm, NormFinder, BestKeeper, and the Comparative ΔCt method were employed to assess the expression of each candidate gene. Overall results reveal that the expression stability of reference genes may differ depending on the statistical program used. YWHAZ, GAPDH, and UBC composed the optimal set of reference genes for the gene expression studies performed by RT-qPCR in our experimental conditions. This work can thus serve as a starting point for the selection of candidate reference genes to normalize the levels of gene expression in endothelial progenitor cell populations.

Evaluating the effectiveness of physician counseling to promote physical activity in Mexico: an effectiveness-implementation hybrid study

Integrating physical activity (PA) counseling in routine clinical practice remains a challenge. The purpose of this study was to evaluate the implementation and effectiveness of a pragmatic strategy aimed to improve physician PA counseling and patient PA. An effectiveness-implementation type-2 hybrid design was used to evaluate a 3-h training (i.e., implementation strategy-IS) to increase physician use of the 5-As (assess, advise, agree, assist, arrange) for PA counseling (i.e., clinical intervention-CI) and to determine if the CI improved patient PA. Patients of trained and untrained physicians reported on PA and quality of life pre-post intervention. Medical charts (N = 1700) were examined to assess the proportion of trained physicians that used the 5-As. The RE-AIM framework informed our evaluation. 305/322 of eligible physicians participated in the IS (M age = 40 years, 52% women) and 683/730 of eligible patients in the CI (M age = 49 years, 77% women). The IS was adopted by all state regions and cost ~ $20 Mexican pesos (US$1) per provider trained. Physician adoption of any of the 5-As improved from pre- to post-training (43 vs. 52%, p < .01), with significant increases in the use of assessment (43 vs. 52%), advising (25 vs. 39%), and assisting with barrier resolution (7 vs. 15%), but not in collaborative goal setting (13 vs. 17%) or arranging for follow-up (1 vs. 1%). Patient PA and quality of life did not improve. The IS intervention was delivered with high fidelity at a low cost, but appears to be insufficient to lead to broad adoption of the CI.

Examining the Relationship between Park Neighborhoods, Features, Cleanliness, and Condition with Observed Weekday Park Usage and Physical Activity: A Case Study

Background

Little research has comprehensively explored how park features, quality indicators, and neighborhood environments are associated with observed park usage and physical activity (PA). This case study examined whether weekday park usage and PA differ by neighborhood type, across numerous categories of park features, and according to park feature condition and cleanliness.

Methods

Direct observation was used to capture the number of users and PA levels within 143 park features in 6 parks (3 urban, 3 suburban) over the course of six weeks. Audits of park environments assessed the type, condition, and cleanliness of all features and amenities.

Results

Urban parks experienced greater usage, but a higher proportion of sedentary users than suburban parks. Usage and PA levels differed across types of park features, with splash pads, pools, paths, and play structures having the greatest proportion of active users. Usage did not differ by park feature condition and cleanliness, but greater condition and cleanliness were generally associated with higher PA levels.

Conclusions

Factors such as neighborhood context, types of park features, and condition and cleanliness can impact park usage and PA levels and should be targets for researchers and planners aiming to foster more user-friendly and active neighborhood park environments.

Applying the RE-AIM conceptual framework for the promotion of physical activity in low- and middle-income countries

ABSTRACT Objective: the RE-AIM framework has been widely used to evaluate internal and external validity of interventions aimed to promote physical activity, helping to provide comprehensive evaluation of the reach, efficacy, adoption, implementation and maintenance of research and programming. Despite this progress, the RE-AIM framework has not been used widely in Latin America. The purpose of this manuscript is to describe the RE-AIM framework, the process and materials developed for a one-day workshop in Guadalajara, and the acceptability and satisfaction of participants that attended the workshop. Methods: lecture, interactive examples and an agenda were developed for a one-day RE-AIM workshop over a three month period. Results: thirty two health care practitioners (M age = 30.6, SD=9.9 years) attended the workshop. Most (100%) rated the workshop as credible, useful (100%) and intended to apply it in current or future research (95%). Conclusion: results suggest intuitive appeal of the RE-AIM framework, and provide a strategy for introducing the utility and practical application of the framework in practice settings in Mexico and Latin America.

Enhancing Indigenous Health Promotion Research Through Two-Eyed Seeing: A Hermeneutic Relational Process

The intention of this article is to demonstrate how Indigenous and allied health promotion researchers learned to work together through a process of Two-Eyed Seeing. This process was first introduced as a philosophical hermeneutic research project on diabetes prevention within an Indigenous community in Quebec Canada. We, as a research team, became aware that hermeneutics and the principles of Haudenosaunee decision making were characteristic of Two-Eyed Seeing. This article describes our experiences while working with each other. Our learning from these interactions emphasized the relational aspects needed to ensure that we became a highly functional research team while working together and becoming Two-Eyed Seeing partners.

A planar model of the vessel wall from cellularized-collagen scaffolds: focus on cell–matrix interactions in mono-, bi- and tri-culture models

An easy to prepare and manipulate model of the vascular wall in a planar shape to investigate physiological and pathological processes of vascular tissues.

Physical activity interventions to promote positive youth development among indigenous youth: a RE-AIM review

Physical activity (PA) programs are a promising strategy to promote positive youth development (PYD). It is not known if published reports provide sufficient information to promote the implementation of effective PYD in indigenous youth. The purpose of this study was to assess the extent to which published literature on PA programs that promote PYD in indigenous youth report on RE-AIM (reach, effectiveness, adoption, implementation, maintenance) indicators. A systematic literature search was conducted to identify articles reporting on PA programs that promote PYD in indigenous youth. The search yielded 8084 articles. A validated 21-item RE-AIM abstraction tool assessing internal and external validity factors was used to extract data from 10 articles meeting eligibility criteria. The most commonly reported dimensions were effectiveness (73 %), adoption (48 %), and maintenance (43 %). Reach (34 %) and implementation (30 %) were less often reported. Published research provides insufficient information to inform real-world implementation of PA programs to promote PYD in indigenous youth.

Influence of parental perception of school safety and gender on children's physical activity in Mexico: A cross sectional study

OBJECTIVE

This cross sectional study aims to determine the effects of gender and parental perception of safety at school on children's physical activity (PA) levels.

MATERIALS AND METHODS

Parents of school aged Mexican children residing in Guadalajara, Mexico City, and Puerto Vallarta, completed surveys about their children's PA measures. The physical activity indicators were evaluated using linear and logistical regression models.

RESULTS

Analysis did not indicate that gender moderated the relationship between parental perception of safety and PA measures, but significant gender issues exist with girls participating less than boys in the three measures of PA in this study (p<0.001).

CONCLUSION

Results suggest the need for additional interventions promoting physical activity in girls in Mexico.

Assessing the physical activity environment in Mexican healthcare settings

OBJECTIVE

To assess the informational, educational and instrumental environments among Mexican healthcare settings for their potential to promote physical activity (PA).

MATERIALS AND METHODS

The Environmental Physical Activity Assessment Tool for Healthcare Settings (EPATHS) was developed to assess the PA environments of 40 clinics/hospitals representing the three Mexican healthcare systems in Guadalajara. The EPATHS assessed the presence and quality of PA enhancing features in the informational (e.g. signage), educational (e.g. pamphlets), and instrumental (e.g. stairs) environments of included clinics/hospitals.

RESULTS

28 (70%) clinics/hospitals had more than one floor with stairs; 60% of these had elevators. Nearly 90% of stairs were visible, accessible and clean compared to fewer than 30% of elevators. Outdoor spaces were observed in just over half (55%) of clinics/hospitals, and most (70%) were of good quality. Only 25% clinics/hospitals had educational PA materials.

CONCLUSIONS

The PA instrumental environment of Mexican healthcare settings is encouraging. The informational and educational environments could improve.

Promoting healthful diet and physical activity in the Mexican school system for the prevention of obesity in children

OBJECTIVE

This paper describes the rationale, design, and methods of a two-year randomized controlled trial conducted to evaluate the effectiveness of an environmental intervention in 27 elementary schools in Mexico City.

MATERIALS AND METHODS

There were two units of analysis, school level addressing changes in elementary public part-time schools, and individual-level addressing behavioral changes in students 9 to 11 years of age. Two intensities of an intervention program were implemented (basic and plus), each containing two intervention components: physical activity and nutrition, supported by a communication/education component. Evaluation of the intervention was carried out during the school cycles 2006-2007 and 2007-2008.

RESULTS

Primary outcomes were overweight and obesity prevalence and fitness; environmental and behavioural measures were also examined.

CONCLUSIONS

This is the first institutional multilevel, multifactorial project, consistent with the best practices available in current literature, carried out in Mexico to prevent childhood obesity in schools.

Impact of a school-based intervention program on obesity risk factors in Mexican children

OBJECTIVE

To evaluate the impact of an 18-month school obesity prevention intervention on the health behaviors of 4th and 5th grade students based on ecological principles and formative research conducted in Mexico.

MATERIALS AND METHODS

A Randomized Control Trial (RCT), design was used to assign 27 schools to one of three conditions: basic or plus interventions and control. School environment measures, children's eating and physical activity behaviors, and body mass index were assessed four times over a 2-year period in a sample of 830 students.

RESULTS

In the intervention schools, the availability of healthy foods increased with a concomitant decrease in unhealthy food availability. Food intake showed the same trend. In the intervention schools, children did not engage in more moderate to vigorous physical activity (MVPA) in physical education (PE) class or recess but increased steps taken. Obesity prevalence did not change.

CONCLUSION

The intervention improved the school food environment and child healthy behaviors.

The Influence of Physical Education Lesson Context and Teacher Behaviour on Student Physical Activity in Mexico (La influencia del contexto de la clase de Educación física y de los comportamientos docentes en la actividad física de los alumnos en México)

Abstract. Objective: To explore the influence of physical education (PE) lesson context and teacher behaviour on moderate-to-vigorous physical activity (MVPA) in Mexican children during PE class. Methods: Trained observers rated the physical activity intensity (lying down, sitting, standing, walking, vigorous movement) of 232 students from grades 3 to 5, PE lesson context (management, general knowledge, fitness knowledge, fitness, skill practice, game play, free play), and teacher behaviour (promoting fitness, demonstrating, instructing, observing, managing, other task) during PE class in 20 public elementary schools in Mexico City using the System for Observing Fitness Instruction Time (SOFIT). Regressions with backward elimination were conducted. Results: Class duration was on average 33.6 minutes (SD=7.9). Boys (M=14.8 min, SD=6.8) spent more time in MVPA than girls (M=12.6 min, SD=6.1; p<.01). For boys, a model including game play (b= 1.04, p<.001), skill practice (b=.54, p<.01), and fitness (b =.53, p<.05) explained 45% of the variance in MVPA (p<.05). For girls, a model including fitness (b= .49, p<.05), fitness knowledge (b= .19, p<.05), and other task (b=.35, p<.05) explained 38% of the variance in MVPA (p<.05). Conclusion: Strategies and policies aimed at improving child physical activity levels during PE class should endorse the effective instruction and execution of fitness, game play, skill practice and PE lesson contexts.Resumen. Objetivo: Explorar la influencia del contexto de las clases de educación física (EF) y el comportamiento del maestro en la actividad física moderada-vigorosa (AFMV) en niños mexicanos. Métodos: Usando el método Sistema de Observación del Tiempo de Instrucción de la condición Física (SOFIT). Observadores entrenados midieron la intensidad de la actividad física (acostado, sentado, de pie, caminando, movimiento vigoroso) de 232 estudiantes de 3ro a 5to grado, el contexto de la clase, (gestión, conocimiento general, conocimiento de la condición física, condición física, práctica de habilidades, juego, juego libre), y el comportamiento del maestro (promoción de la condición física, demostración, instrucción, observación, gestión, otra tarea) durante la clase de EF en 20 escuelas públicas de educación primaria de la ciudad de México mediante el SOFIT. Se llevaron a cabo regresiones múltiples. Resultados: La duración promedio de las clases observadas fue de 33,6 minutos (DE = 7,9). Los niños (M = 14,8 min, DE = 6,8) pasaron más tiempo en AFMV que las niñas (M = 12,6 min, DE = 6,1; p <0,01). En niños, el tiempo de clase dedicado al juego (β= 1.04, p <.001), la práctica de habilidades (β = .54, p <.01) y la condición física (β = .53, p <.05) explico el 45% de la varianza en AFMV (p <.05). En niñas, el tiempo de clase dedicado a la condición física (β= .49, p <.05), al conocimiento sobre la condición física (β= .19, p <.05), y otras tarea (β= .35, p <.05) explico  el 38% de la varianza en AFMV (p <.05).Para los niños, un modelo incluyendo el juego (b = 1,04, p <0,001), el desarrollo de habilidades prácticas (b = 0,54, p <0,01), y la condición física (b = 0,53, p <0,05) explicaron el 45% de la varianza en AFMV (p <0,05). Para las niñas, un modelo incluyendo la condición física (b = 0,49, p <0,05), el conocimiento de la condición física (b = 0,19, p <0,05), y otras tarea (b = 0,35, p <0,05) explican el 38% de la varianza en AFMV (p <0,05). Conclusión: Las estrategias y políticas encaminadas a la mejora de los niveles de actividad física de los niños durante la clase de EF deben suscribir la enseñanza efectiva y la promoción de la condición física, el juego, y el desarrollo de las habilidades prácticas.

Physical activity prescription among Mexican physicians: a structural equation analysis of the theory of planned behaviour

AIM

To describe the physical activity (PA) prescribing behaviour of Mexican primary care physicians and determine if the theory of planned behaviour (TPB) explains this behaviour.

METHODS

633 physicians (56% male, mean age 38 years) from 305 primary care clinics in Jalisco, Mexico self-reported PA prescription behaviour, PA involvement, attitude, subjective norm, perceived behavioural control (PBC) and intention related to PA prescription behaviour. Structural equation modelling (SEM) was employed.

RESULTS

48% of physicians reported they always ask patients about their PA, 33% provide verbal prescriptions, 6% provide written prescriptions, 8% refer patients to PA resources and 4% assess patient fitness. SEM analysis showed that the fit of the TPB model was satisfactory (RMSEA = 0.05, CFI = 0.98, SRMR = 0.05). The model explained 79% of the variance on intention (r(2) = 0.79, p < 0.05), and 14% of the variance on prescription behaviour (r(2) = 0.14, p < 0.05). Subjective norm (β = 0.73, p < 0.05) and attitude (β = 0.16, p < 0.05) explained behavioural intention, while PBC (β = 0.38, p < 0.05) and physician PA (β = 0.15, p < 0.05) explained prescription behaviour.

DISCUSSION

The TPB provided useful insight into physician prescription behaviour, although not all the theory tenets were supported. More research testing the TPB and other theories is needed to better understand psychosocial predictors of this behaviour.

CONCLUSION

Strategies aimed at improving physicians' perceived ability to prescribe PA and their own PA involvement seem worthwhile.

Correlates of physical activity in First Nations youth residing in First Nations and northern communities in Canada

OBJECTIVES

Physical activity (PA) can help youth achieve balance among physical, mental, emotional and spiritual dimensions of health. The objective was to identify individual, family and community factors associated with PA among First Nations (FN) youth residing in on-reserve and northern FN communities.

METHODS

Participants were 4,837 youth (12-17 years of age) responding to the 2008/10 First Nations Regional Health Survey. Through in-person interviews, youth responded to questions about moderate-to-vigorous physical activity (MVPA), participation in traditional physical activities, and individuallevel, family and community factors.

RESULTS

When averaged across all days of the year, 65% of FN youth accumulated at least 60 min/day of MVPA and 48% of youth participated in at least one traditional FN PA in the previous year. Being male, having a lower number of chronic conditions, living in balance physically, living with at least one biological parent, having more relatives help youth understand their culture, having more community challenges and having more leisure/recreation facilities were independently associated with an increased likelihood of accumulating ≥ 60 min of MVPA. Younger age, being male, knowledge and use of FN language, living in balance spiritually, living with at least one biological parent, having more relatives help youth understand their culture, living in a community of ≤ 300 people, and perceiving the natural environment and community health programs as strengths were independently associated with participation in traditional FN physical activities.

CONCLUSION

There are several correlates of PA from diverse ecological levels among FN youth.

Correlates of physical activity among First Nations children residing in First Nations communities in Canada

OBJECTIVES

Physical activity has numerous mental, emotional, spiritual and physical benefits. The factors influencing physical activity among First Nations children have not been well studied. The objective was to examine the associations between several intrapersonal, family and community factors and physical activity among First Nations school-aged children residing in First Nations communities.

METHODS

Participants consisted of 3,184 children (6-11 years old) from the 2008/10 First Nations Regional Health Survey, a representative sample of First Nations persons who reside in on-reserve and northern First Nations communities. The survey addresses a holistic range of health issues. Primary caregivers completed interviews to assess each child's moderate-to-vigorous physical activity (MVPA), participation in traditional physical activities, six intrapersonal factors, four family factors and two community factors.

RESULTS

Based on primary caregiver reports, 72% of children accumulated a daily average of ≥60 minutes of MVPA and 54% participated in at least one traditional First Nations physical activity in the past year. Older age, having more people in the household, and having more relatives help the child understand their culture were independently associated with accumulating ≥60 minutes of MVPA. School attendance, use of First Nations language, having parents with a high school education, smaller community size, and having more community members help the child understand their culture were independently associated with participation in traditional First Nations physical activities.

CONCLUSION

Among First Nations children, there are several correlates of physical activity from diverse ecological levels.

An ecological and theoretical deconstruction of a school-based obesity prevention program in Mexico

BACKGROUND

Ecological intervention programs are recommended to prevent overweight and obesity in children. The National Institute of Public Health (INSP) in Mexico implemented a successful ecological intervention program to promote healthy lifestyle behaviors in school age children. This study assessed the integration of ecological principles and Social Cognitive Theory (SCT) constructs in this effective school-based obesity prevention program implemented in 15 elementary schools in Mexico City.

METHODS

Two coders applied the Intervention Analysis Procedure (IAP) to "map" the program's integration of ecological principles. A checklist gauged the use of SCT theory in program activities.

RESULTS

Thirty-two distinct intervention strategies were implemented in one setting (i.e., school) to engage four different target-groups (students, parents, school representatives, government) across two domains (Nutrition and Physical Activity). Overall, 47.5% of the strategies targeted the school infrastructure and/or personnel; 37.5% of strategies targeted a key political actor, the Public Education Secretariat while fewer strategies targeted parents (12.5%) and children (3%). More strategies were implemented in the Nutrition domain (69%) than Physical Activity (31%). The most frequently used SCT construct within both intervention domains was Reciprocal Determinism (e.g., where changes to the environment influence changes in behavior and these behavioral changes influence further changes to the environment); no significant differences were observed in the use of SCT constructs across domains.

CONCLUSIONS

Findings provide insight into a promising combination of strategies and theoretical constructs that can be used to implement a school-based obesity prevention program. Strategies emphasized school-level infrastructure/personnel change and strong political engagement and were most commonly underpinned by Reciprocal Determinism for both Nutrition and Physical Activity.

Evaluating the effectiveness of a physical activity referral scheme among women

Evidence supports the effectiveness of interventions delivered in primary care to promote physical activity (PA). Specifically, approaches where physician counseling is coupled with other strategies (eg, referrals to community resources) have been recognized as the most promising. The purpose of this study was to compare the effectiveness of a PA prescription plus referral intervention versus a prescription only intervention delivered in primary care. Ten family physicians and their female patients (N = 35, mean age = 36 years) were randomly assigned to 1 of 3 conditions: prescription plus (n = 12), prescription only (n = 12), and usual care (n = 11). The prescription plus group received a PA prescription plus a referral to a community program, the prescription only group received only the PA prescription, and the usual care group received usual health care. The Godin Leisure-Time Exercise Questionnaire was used to measure PA. A significant increase on the PA score (P < .05, partial η(2) = .178) and on total weekly PA minutes (P < .05, partial η(2) = .179) was observed in both prescription groups after the intervention. There were no significant group differences (P > .05). No PA changes were observed in the usual care group. Findings from this pilot study suggest that brief PA counseling and a prescription delivered in primary care can be effective for promoting PA among women. Referring patients did not seem to enhance the effect on PA.

Community Capacity as an “Inside Job”: Evolution of Perceived Ownership within a University-Aboriginal Community Partnership

Purpose.

To assess the evolution of perceived ownership of a university-Aboriginal community partnership across three project stages.

Design.

Survey administration to project partners during project formalization (1996—T1), mobilization (1999—T2), and maintenance (2004—T3).

Setting.

Aboriginal community of Kahnawake, outside Montreal, Quebec, Canada.

Participants.

Partners involved in influencing decision making in the Kahnawake Schools Diabetes Prevention Project (KSDPP).

Measure and Analysis.

A measure of perceived primary ownership subjected to linear trend analysis.

Results.

KSDPP staff were perceived as primary owner at T1 and shared ownership with Community Advisory Board (CAB) members at T2 and T3. Trend tests indicated greater perceived ownership between T1 and T3 for CAB (χ21 = 12.3, p < .0001) and declining KSDPP staff (χ21 = 10.5, p < .001) ownership over time. Academic partners were never perceived as primary owners.

Conclusion.

This project was community driven from the beginning. It was not dependent on an external academic change agent to activate the community and develop the community's capacity to plan and implement a solution. It still took several years for the grassroots CAB to take responsibility from KSDPP staff, thus indicating the need for sustained funding to build grassroots community capacity.

Ontario's daily physical activity policy for elementary schools: is everything in place for success?

OBJECTIVES

The development, implementation, and evaluation of policies may play an important role in promoting health behaviours such as physical activity. The Ontario Ministry of Education (OME) recently mandated Memorandum No. 138 requiring daily physical activity (DPA) for Ontario elementary students in grades one through eight. The purpose of this paper is to examine implementation strategies.

METHODS

Hogwood and Gunn's 10 preconditions for "perfect implementation" are used to examine publicly available Ministry DPA policy documents to assess whether these implementation strategies have been considered in the policy documents.

RESULTS

Several preconditions (e.g., allocation of resources, task specification) appear to have been considered, however a number of preconditions (e.g., the sustainability of resources, extent to which the policy is valued, and evaluation plans) thought to be important require additional attention to ensure optimal DPA implementation.

CONCLUSIONS

Additional reflection upon Hogwood and Gunn's implementation preconditions would, in our opinion, assist in facilitating optimal DPA implementation as per Memorandum No. 138.

Risk of upper gastrointestinal bleeding with oral bisphosphonates and non steroidal anti-inflammatory drugs: a case-control study

BACKGROUND

Gastrointestinal injuries including gastric ulcers have been reported with oral bisphosphonate therapy. However, the risk of the more serious upper gastrointestinal bleeding (UGB) especially in the community setting with these drugs remains unknown. Similarly, the risk of UGB among users of both bisphosphonates and non steroidal anti-inflammatory drugs (NSAIDs) in the community is also unknown.

AIM

To explore the risk of more serious UGB among users of bisphosphonates and the risk of UGB among users of both bisphosphonates and NSAIDs in the community.

METHODS

We conducted a case-control study within a cohort of Quebec residents who had received a revascularization procedure from 1995 to 2004. Cohort members were followed up from the date of their first procedure until the earliest of: (1) study outcome, (2) date of death or (3) end of health care coverage. Cases were defined as those with the first diagnosis of a UGB. For each case, 20 controls were selected and matched to the cases by index date, age and cohort entry. Adjusted odds ratios for current use of bisphosphonates, NSAIDs and co-therapy of both drugs were computed.

RESULTS

Within the initial cohort, 3253 incident cases of UGBs and corresponding 65 060 matched controls were identified. The adjusted odds ratio (OR) for UGB by current users of bisphosphonates was 1.01 (95% CI, 0.72-1.43). Current NSAID use was associated with an increased risk of UGB OR = 1.75; 95% CI, 1.53-1.99. The OR for use of bisphosphonates and NSAIDs was elevated OR = 2.00; 95% CI, 1.12-3.57. This risk was still elevated for users of bisphosphonates and COX-2 inhibitors [OR = 2.38 (95% CI, 1.26-4.50)].

CONCLUSION

We found no evidence of an increase in the risk of UGB among current users of bisphosphonates. The risk of combined NSAID and bisphosphonate therapy was increased, but this risk was not higher than the risk for NSAID users alone.

Ontario's daily physical activity policy for elementary schools: is everything in place for success?

OBJECTIVES

The development, implementation, and evaluation of policies may play an important role in promoting health behaviours such as physical activity. The Ontario Ministry of Education (OME) recently mandated Memorandum No. 138 requiring daily physical activity (DPA) for Ontario elementary students in grades one through eight. The purpose of this paper is to examine implementation strategies.

METHODS

Hogwood and Gunn's 10 preconditions for "perfect implementation" are used to examine publicly available Ministry DPA policy documents to assess whether these implementation strategies have been considered in the policy documents.

RESULTS

Several preconditions (e.g., allocation of resources, task specification) appear to have been considered, however a number of preconditions (e.g., the sustainability of resources, extent to which the policy is valued, and evaluation plans) thought to be important require additional attention to ensure optimal DPA implementation.

CONCLUSIONS

Additional reflection upon Hogwood and Gunn's implementation preconditions would, in our opinion, assist in facilitating optimal DPA implementation as per Memorandum No. 138.

Can the democratic ideal of participatory research be achieved? An inside look at an academic-indigenous community partnership

Democratic or equal participation in decision making is an ideal that community and academic stakeholders engaged in participatory research strive to achieve. This ideal, however, may compete with indigenous peoples' right to self-determination. Study objectives were to assess the perceived influence of multiple community (indigenous) and academic stakeholders engaged in the Kahnawake Schools Diabetes Prevention Project (KSDPP) across six domains of project decision making and to test the hypothesis that KSDPP would be directed by community stakeholders. Self-report surveys were completed by 51 stakeholders comprising the KSDPP Community Advisory Board (CAB), KSDPP staff, academic researchers and supervisory board members. KSDPP staff were perceived to share similar levels of influence with (i) CAB on maintaining partnership ethics and CAB activities and (ii) academic researchers on research and dissemination activities. KSDPP staff were perceived to carry significantly more influence than other stakeholders on decisions related to annual activities, program operations and intervention activities. CAB and staff were the perceived owners of KSDPP. The strong community leadership aligns KSDPP with a model of community-directed research and suggests that equitable participation-distinct from democratic or equal participation-is reflected by indigenous community partners exerting greater influence than academic partners in decision making.

Partnering with libraries to promote walking among community-dwelling adults: a Kingston gets active pilot pedometer-lending project

Most adults do not walk enough to obtain health benefits. Pedometers have been successfully utilized to motivate and increase walking. Given that libraries are a place where community members seek health resources, they are a logical setting for increasing community accessibility to pedometers. The purpose was to examine the feasibility of lending pedometers to library patrons to increase walking. In five Canadian public libraries, 90 pedometers were made available for 6 months. A total of 41 library patrons (33 women, 8 men, age range 18 to 65 or older) completed a survey about their walking patterns and pedometer use. More than 330 loans were made. Chisquare analysis found significant associations between walking and motivation to walk more (p < .05), walking and goal setting (p < .05), and motivation to walk more and setting a walking goal (p < .001). Results provide preliminary evidence that lending pedometers through local libraries is an effective, low-cost approach to enhance walking in community members.

Perceived community environment and physical activity involvement in a northern-rural Aboriginal community

BACKGROUND

Type 2 diabetes disproportionately affects Aboriginal peoples in Canada. Ample evidence shows that regular physical activity (PA) plays an important role in the prevention and treatment of type 2 diabetes. Evidence is beginning to emerge linking PA to the physical environment but little is known about the relationship between remote rural environments and PA involvement in Aboriginal peoples. This study's purpose was to investigate the relationship between perceptions of the environment and PA and walking patterns in Aboriginal adults in order to inform the planning and implementation of community-relevant PA interventions.

METHODS

Two hundred and sixty three residents (133 women, mean age = 35.6 years, SD = 12.3 and 130 men, mean age = 37.2 years, SD = 13.1) from Moose Factory, Ontario were asked about environmental factors related to walking and PA involvement. Survey items were drawn from standardized, validated questionnaires. Descriptive statistics (means, standard deviations, percentages) were calculated. A series of hierarchical multiple regressions were performed to determine associations between walking and overall PA with perceived environmental variables.

RESULTS

Hierarchical multiple regression to predict walking revealed significant associations between walking and perceived safety and aesthetics. Owning home exercise equipment predicted strenuous PA. Different aspects of the physical environment appear to influence different types of physical activities. The significant amount of variance in behaviour accounted for by perceived environmental variables (5.3% walking) included safety, aesthetics, convenience, owning home exercise equipment and comfortable shoes for walking.

CONCLUSION

Results suggest that a supportive physical environment is important for PA involvement and that walking and activities of different intensity appear to be mediated by different perceived environmental variables. Implications for PA promotion in rural environments where Aboriginal people face many unique environmental features (e.g., bears, mosquitoes, extreme cold) are discussed.

Using an analytic framework to identify potential targets and strategies for ecologically based physical activity interventions in middle schools

The objective was to demonstrate the value of applying an ecological analytic framework to formative data in conjunction with ecological planning frameworks (e.g., intervention mapping) to ensure a high degree of ecological program integration as illustrated through a physical activity program for students in middle school. Eight focus groups were conducted with 38 students in four schools to examine student perceptions of who or what in their school made it easy or difficult for students to be physically active. Qualitative data were used to identify potential intervention targets according to the analytic framework. Frequency analysis revealed that most identified physical activity barriers/facilitators were associated with organization (59.4%) targets. Five different intervention strategies were identified, with organizational modification being most popular. Applying the analytic framework to formative data enabled us to identify potential targets, strategies, and activities for an ecologically based physical-activity-promotion program relevant to the priority population.

Surface plasmon photonic bandgap in azopolymer gratings sputtered with gold

Surface plasmons (SPs) are generated on a doubly corrugated gold-covered surface. The corrugations were obtained by direct holographic inscription of surface relief gratings on an azopolymer film. This method permits the superposition of multiple surface profiles with easy control of the grating spacing. One grating is inscribed to act as coupler for the incident light to the SP and a second grating is inscribed to generate a gap in the SP dispersion curve. The coupling and the gap can be observed by measuring the reflectivity of the gold surface as a function of the angle of incidence and the wavelength of the probe beam.

Unpacking the black box: a deconstruction of the programming approach and physical activity interventions implemented in the Kahnawake Schools Diabetes Prevention Project

An ecological lens was used to deconstruct the programming approach and unpack physical activity interventions implemented through the Kahnawake Schools Diabetes Prevention Project. Despite a surge of interest in ecologically based health promotion programming, optimal combinations of interventions and programming approaches to promote community physical activity involvement have not been systematically studied. The authors obtained physical activity intervention descriptions through archive retrieval and face-to-face interviews with intervention staff. Programming approach, intervention targets, strategies for change, and delivery settings were assessed by applying the intervention analysis procedure to intervention descriptions. A complex intervention package was found containing a host of multitarget, multisetting intervention strategies designed and implemented through dynamic exchanges between a diversity of community partners. This study provides a first step toward better understanding community intervention packages and programming strategies for promoting physical activity involvement within a community setting.

Impact of a diabetes prevention program on body size, physical activity, and diet among Kanien'keha:ka (Mohawk) children 6 to 11 years old: 8-year results from the Kahnawake Schools Diabetes Prevention Project

OBJECTIVES

Report the 8-year impact on body size, physical activity, and diet of a community-based diabetes prevention program for elementary-school children in a Kanien'keha:ka (Mohawk) community in Canada.

METHODS

Follow-up (1994-1996) of subjects in the intervention and comparison community and repeat cross-sectional measurements in the intervention community alone from 1994 to 2002. Measures included triceps and subscapular skinfold thicknesses, body mass index (BMI), weekly number of 15-minute episodes of physical activity, run/walk test times, television watching, and consumption of sugared foods, fatty foods, and fruits and vegetables.

RESULTS

The longitudinal data of 1994-1996 showed some early positive effects of the program on skinfold thickness but not on BMI, physical activity, fitness, or diet. Repeat cross-sectional measures from 1994 to 2002 showed increases in skinfold thickness and BMI. Physical activity, fitness, and television watching showed favorable trends from 1994 to 1999 that were not sustained in 2002. Key high-fat and high-sugar foods consumption decreased, as did consumption of fruits and vegetables.

CONCLUSIONS

Although early results showed some successes in reducing risk factors for type 2 diabetes, these benefits were not maintained over 8 years.

Understanding the outcomes of a psycho-educational group intervention for caregivers of persons with dementia living at home: a process evaluation

This qualitative process evaluation study aimed to identify the primary processes of a psycho-educational group for caregivers of persons with dementia, in order to better understand intervention outcomes. Semi-structured interviews were conducted with 30 participants recruited from the experimental group of a randomised controlled trial. At pre-test, participants reported their expectations of the group. At post-test, they described their group experience, the most/least helpful aspects of the intervention, their most useful learning and their responses during a recent episode of disturbing behaviour by their relative. Results showed that the group delivered both educational and support processes. Support processes complemented educational processes. Participants learned coping strategies, with reframing playing a more important role than problem-solving or seeking social support. Daughters benefited more than spouses from educational processes. This study of group processes contributes to our understanding of the reported reduction in frequency of disturbing behaviours and of the change in caregivers' behaviours.

Development of the Physical Activity Interactive Recall (PAIR) for Aboriginal children

BACKGROUND: Aboriginal children in Canada are at increased risk for type 2 diabetes. Given that physical inactivity is an important modifiable risk factor for type 2 diabetes, prevention efforts targeting Aboriginal children include interventions to enhance physical activity involvement. These types of interventions require adequate assessment of physical activity patterns to identify determinants, detect trends, and evaluate progress towards intervention goals. The purpose of this study was to develop a culturally appropriate interactive computer program to self-report physical activity for Kanien'kehá:ka (Mohawk) children that could be administered in a group setting. This was an ancillary study of the ongoing Kahnawake Schools Diabetes Prevention Project (KSDPP). METHODS: During Phase I, focus groups were conducted to understand how children describe and graphically depict type, intensity and duration of physical activity. Sixty-six students (40 girls, 26 boys, mean age = 8.8 years, SD = 1.8) from four elementary schools in three eastern Canadian Kanien'kehá:ka communities participated in 15 focus groups. Children were asked to discuss and draw about physical activity. Content analysis of focus groups informed the development of a school-day and non-school-day version of the physical activity interactive recall (PAIR). In Phase II, pilot-tests were conducted in two waves with 17 and 28 children respectively to assess the content validity of PAIR. Observation, videotaping, and interviews were conducted to obtain children's feedback on PAIR content and format. RESULTS: Children's representations of activity type and activity intensity were used to compile a total of 30 different physical activity and 14 non-physical activity response choices with accompanying intensity options. Findings from the pilot tests revealed that Kanien'kehá:ka children between nine and 13 years old could answer PAIR without assistance. Content validity of PAIR was judged to be adequate. PAIR was judged to be comprehensive, acceptable, and enjoyable by the children. CONCLUSIONS: Results indicate that PAIR may be acceptable to children between nine and 13 years old, with most in this age range able to complete PAIR without assistance. The flexibility of its programming makes PAIR an easily adaptable tool to accommodate diverse populations, different seasons, and changing trends in physical activity involvement.

Community governance of the Kahnawake Schools Diabetes Prevention Project, Kahnawake Territory, Mohawk Nation, Canada

Health promotion emphasizes the importance of community ownership in the governance of community-based programmes, yet little research has been conducted in this area. This study examined perceptions of community ownership among project partners taking responsibility for decision-making related to the Kahnawake Schools Diabetes Prevention Project (KSDPP). Project partners were surveyed cross-sectionally at 18 months (T1) and 60 months (T2) into the project. The perceived influence of each project partner was assessed at T1 and T2 for three domains: (i) KSDPP activities; (ii) KSDPP operations; and (iii) Community Advisory Board (CAB) activities. Project staff were perceived to have the greatest influence on KSDPP activities, KSDPP operations and CAB activities at both T1 and T2. High mean scores of perceived influence for CAB members and community researchers, however, suggests that project decision-making was a shared responsibility among multiple community partners. Although academic researcher influence was consistently low, they were satisfied with their level of influence. This was unlike community affiliates, who were less satisfied with their lower level of influence. In keeping with Kanien'kehaka (Mohawk) culture, the findings suggest a participatory democracy or shared decision-making as the primary mode of governance of KSDPP.

The process of a group intervention for caregivers of demented persons living at home: conceptual framework, components, and characteristics

Most earlier group interventions for caregivers of demented persons lacked a theoretical basis to guide the intervention process and focused on providing information and practical advice and encouraging the expression of feelings. This article presents the process of a group intervention with emphasis on its conceptual framework, components and characteristics. As caregivers are exposed to numerous daily stressful demands, the intervention's conceptual framework was derived from Lazarus and Folkman's transactional theory of stress and coping and Folkman's Coping Effectiveness Training Program. The central aim of the intervention was to improve the ability of caregivers to cope with the stressful demands at the core of caring for a demented person, rather than to focus on information and the task-oriented aspects of caring. The two components of the intervention deal with the cognitive appraisal of stressors and coping strategies, with a view to determining which strategies are most appropriate on the basis of the changeability of stressors. Three coping strategies were proposed: problem solving (problem-focused coping to deal with changeable stressors), reframing (emotion-focused coping to manage the emotional response to unchangeable stressors), and seeking social support (problem- or emotion-focused coping). The most salient characteristics of this group intervention were its intensity (15 meetings) and its focus on the caregivers' daily reality, which provided concrete reference points for the discussion of conceptual notions.

Presenilin function: connections to Alzheimer's disease and signal transduction

Missense mutations in presenilin 1 (PS1) and presenilin 2 (PS2) are associated with early-onset familial Alzheimer's disease which displays an accelerated deposition of amyloid plaques and neurofibrillary tangles. Presenilins are multi-spanning transmembrane proteins which localize primarily to the endoplasmic reticulum and the Golgi compartments. We have previously demonstrated that PS1 exists as a high-molecular-mass complex that is likely to contain several functional ligands. Potential binding proteins were screened by the yeast two-hybrid system using the cytoplasmically orientated PS1 loop domain which was shown to interact strongly with members of the armadillo family of proteins, including beta-catenin, p0071 and a novel neuron-specific plakophilin-related armadillo protein (NPRAP). Armadillo proteins can have dual functions that encompass the stabilization of cellular junctions/synapses and the mediation of signal transduction pathways. Our observations suggest that PS1 may contribute to both aspects of armadillo-related pathways involving neurite outgrowth and nuclear translocation of beta-catenin upon activation of the wingless (Wnt) pathway. Alzheimer's disease (AD)-related presenilin mutations exhibit a dominant gain of aberrant function resulting in the prevention of beta-catenin translocation following Wnt signalling. These findings indicate a functional role for PS1 in signalling and suggest that mistrafficking of selected presenilin ligands may be a potential mechanism in the genesis of AD.

RNA export mediated by tap involves NXT1-dependent interactions with the nuclear pore complex

Nuclear export of ribonucleoprotein complexes requires cis-acting signals and recognition by receptors that mediate translocation through the nuclear pore complex. Translocation is likely to involve a series of physical interactions between the ribonucleoprotein complex and nucleoporins within the nuclear pore complex. Here, we have characterized the function of NXT1 in the context of the Tap-dependent RNA export pathway. Tap has been implicated in the nuclear export of RNA transcripts derived from Mason-Pfizer monkey virus that contain the constitutive transport element. We demonstrate that NXT1 stimulates binding of a Tap-RNA complex to nucleoporins in vitro, and we provide mutational analysis that shows these interactions are necessary for nuclear export of an intron-containing viral mRNA in vivo. Tap contains separate domains for binding to nucleoporins and NXT1, both of which are critical for its export function. RNA export is mediated by a heterodimer of Tap and NXT1, and the function of NXT1 on this pathway is to regulate the affinity of the Tap-RNA complex for nucleoporins within the nuclear pore complex. We propose that NXT1-dependent binding of the Tap-RNA complex to the nucleoporin p62, which we have reconstituted in vitro using recombinant proteins, represents a single step of the translocation reaction.

Mental health, stress correlates and psychotropic drug use or non-use among aged caregivers to elders with dementia

The goal of the study was to compare caregivers who used psychotropic drugs with caregivers who were non-users in order to pinpoint differences in coping styles between the two groups. We performed a secondary analysis of a study on the stress and psychological well-being of persons caring for relatives with dementia. We compared elderly caregivers, as either psychotropic drug users (n = 61) or non-users (n = 133), over various psychosocial characteristics relating to the care-giving context. Results reveal that users, as compared to non-users were: (a) more disturbed (appraised a greater stress) by the relative's dysfunctional behaviours, after controlling for the frequency of the behaviours; and (b) experienced more conflict during interpersonal interactions, although their appraisal of self-satisfaction with formal and informal support to their care-giving activities did not differ significantly. Strikingly, users combined and called on a greater number of problem-focused and emotion-reducing coping strategies than did non-users. They more frequently used affective regulation and information seeking coping styles. Stress-related measures (especially stress appraisal and conflict) contributed more to the variation in mental distress of users than of non-users. Results provide a theoretical and empirical rationale for therapeutic interventions such as the cognitive behavioural approach.

Brain expression of presenilins in sporadic and early-onset, familial Alzheimer's disease

BACKGROUND

Mutations in the presenilin proteins cause early-onset, familial Alzheimer's disease (FAD).

MATERIALS AND METHODS

We characterized the cellular localization and endoproteolysis of presenilin 2 (PS2) and presenilin 1 (PS1) in brains from 25 individuals with presenilin-mutations causing FAD, as well as neurologically normal individuals and individuals with sporadic Alzheimer's disease (AD).

RESULTS

Amino-terminal antibodies to both presenilins predominantly decorated large neurons. Regional differences between the broad distributions of the two presenilins were greatest in the cerebellum, where most Purkinje cells showed high levels of only PS2 immunoreactivity. PS2 endoproteolysis in brain yielded multiple amino-terminal fragments similar in size to the PS1 amino-terminal fragments detected in brain. In addition, two different PS2 amino-terminal antibodies also detected a prominent 42 kDa band that may represent a novel PS2 form in human brain. Similar to PS1 findings, neither amino-terminal nor antiloop PS2 antibodies revealed substantial full-length PS2 in brain. Immunocytochemical examination of brains from individuals with the N141I PS2 mutation or eight different PS1 mutations, spanning the molecule from the second transmembrane domain to the large cytoplasmic loop domain, revealed immunodecoration of no senile plaques and only neurofibrillary tangles in the M139I PS1 mutation stained with PS1 antibodies.

CONCLUSIONS

Overall presenilin expression and the relative abundance of full-length and amino-terminal fragments in presenilin FAD cases were similar to control cases and sporadic AD cases. Thus, accumulation of full-length protein or other gross mismetabolism of neither PS2 nor PS1 is a consequence of the FAD mutations examined.

Ligand specific effects on aluminum incorporation and toxicity in neurons and astrocytes

Aluminum is present in many manufactured foods and medicines and is added to drinking water for purification purposes. It has been proposed that aluminum is a contributing factors to several neurodegenerative disorders such as Alzheimer's disease. However, this remains controversial primarily due to the unusual properties of aluminum and a lack of information on its cellular sites of action. To resolve some of these questions, we have examined aluminum uptake in both neuronal and astroglial cells as well as the role of metal speciation. The relative accumulation of four aluminum salts, aluminum maltolate, aluminum lactate, aluminum chloride and aluminum fluoride, was investigated and correlated with cell viability and intracellular distribution as determined by morin staining. Significant differences in aluminum incorporation and toxicity were observed in both neuronal and glia cells with the largest effects exhibited by the maltol species. This was accompanied by a nuclear accumulation in the neuronal cell line that was contrasted by the perinuclear, vesicular distribution in astrocytes that partially co-localized with cathepsin D, a lysosomal marker. These findings demonstrate differences in aluminum species and highlights the importance of these factors in modulating the toxic effect of aluminum.

Presenilin structure, function and role in Alzheimer disease

Numerous missense mutations in the presenilins are associated with the autosomal dominant form of familial Alzheimer disease. Presenilin genes encode polytopic transmembrane proteins, which are processed by proteolytic cleavage and form high-molecular-weight complexes under physiological conditions. The presenilins have been suggested to be functionally involved in developmental morphogenesis, unfolded protein responses and processing of selected proteins including the beta-amyloid precursor protein. Although the underlying mechanism by which presenilin mutations lead to development of Alzheimer disease remains elusive, one consistent mutational effect is an overproduction of long-tailed amyloid beta-peptides. Furthermore, presenilins interact with beta-catenin to form presenilin complexes, and the physiological and mutational effects are also observed in the catenin signal transduction pathway.

Resolution of allelic and non-allelic variants of histone H1 by cation-exchange-hydrophilic-interaction chromatography

A mixed-mode high-performance liquid chromatography (HPLC) method that resolves the six known non-allelic variants of chicken erythrocyte histone H1 is described. Common, but previously unknown, allelic variants of H1 that comigrate in polyacrylamide gel electrophoresis are also resolved. The resolution of H1 variants achieved by this method should be useful in determining the functional significance of H1 sequence heterogeneity and in analyses of post-translational modification of H1. Furthermore, the principles behind the separation should be applicable to analyses of polymorphism in other proteins.

RanGTP-binding protein NXT1 facilitates nuclear export of different classes of RNA in vitro

To better characterize the mechanisms responsible for RNA export from the nucleus, we developed an in vitro assay based on the use of permeabilized HeLa cells. This new assay supports nuclear export of U1 snRNA, tRNA, and mRNA in an energy- and Xenopus extract-dependent manner. U1 snRNA export requires a 5' monomethylated cap structure, the nuclear export signal receptor CRM1, and the small GTPase Ran. In contrast, mRNA export does not require the participation of CRM1. We show here that NXT1, an NTF2-related protein that binds directly to RanGTP, strongly stimulates export of U1 snRNA, tRNA, and mRNA. The ability of NXT1 to promote export is dependent on its capacity to bind RanGTP. These results support the emerging view that NXT1 is a general export factor, functioning on both CRM1-dependent and CRM1-independent pathways of RNA export.