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1.
Scand J Rheumatol ; 50(6): 417-426, 2021 Nov.
Article in English | MEDLINE | ID: mdl-33775211

ABSTRACT

Objectives: Previous studies of high-resolution peripheral quantitative computed tomography (HR-pQCT) imaging of hand joints in patients with rheumatoid arthritis (RA) have suggested that erosion healing may occur. Our objective was to examine changes in erosion volume, joint space width (JSW), bone mineral density (BMD), and bone remodelling, and their association with clinical outcomes and measures of patient hand function.Method: We examined 48 patients who achieved a good response to a newly initiated biologic therapy. HR-pQCT images of the dominant hands' second and third metacarpophalangeal joints were obtained 3 and 12 months after therapy initiation. Bone erosion volume, JSW, BMD, and bone remodelling were quantified from HR-pQCT images, with improvement, no change (unchanged), or progression in these measures determined by least significant change. Disease activity and hand function measures were collected.Results: There were no significant group changes in HR-pQCT outcomes over the 9 month period. Twenty-two patients had total erosion volumes that remained unchanged, nine showed improvement, and two progressed. The majority of JSW and BMD measures remained unchanged. There was a significant association between the baseline Health Assessment Questionnaire score and the change in minimum JSW, but no other significant associations between HR-pQCT outcomes and function were observed.Conclusions: The vast majority of patients maintained unchanged JSW and BMD over the course of follow-up. Significant improvements in total erosion volume occurred in 27% of patients, suggesting that biologic therapies may lead to erosion healing in some patients, although this did not have an impact on self-reported and demonstrated hand function.


Subject(s)
Antirheumatic Agents , Arthritis, Rheumatoid , Biological Products , Biological Therapy , Antirheumatic Agents/pharmacology , Arthritis, Rheumatoid/diagnostic imaging , Arthritis, Rheumatoid/drug therapy , Biological Products/pharmacology , Bone Density/drug effects , Bone Density/physiology , Humans , Metacarpophalangeal Joint/drug effects , Metacarpophalangeal Joint/physiology , Treatment Outcome
2.
Osteoarthritis Cartilage ; 26(7): 929-939, 2018 07.
Article in English | MEDLINE | ID: mdl-29678623

ABSTRACT

OBJECTIVE: Anterior cruciate ligament (ACL) tears increase early onset osteoarthritis (OA) risk leading to cartilage and bone degradation. While the contribution of bone in OA development is unclear, evidence suggests that bone changes accompany cartilage degradation. This study aims to assess if regions with differences in subchondral bone plate thickness have differences in cartilage thickness when comparing ACL reconstructed (ACLR) knees of women ≥5 years post-injury to contralateral and controls with uninjured knees. DESIGN: Magnetic resonance imaging (MRI) assessed cartilage and high resolution peripheral quantitative computed tomography (HR-pQCT) assessed subchondral bone in both knees. Multimodal 3D image registration aligned anatomy. Maps of the spatial distribution of thickness on the articular surfaces were generated to compare women with ACL reconstructions to contralateral and controls with uninjured knees. RESULTS: ACLR knees had a thicker subchondral bone plate in the posterior and central lateral femur compared to contralateral knees (10.4% and 4.2% thicker, P = 0.032 and 0.032, W = 108 and 107, respectively) and in the posterior lateral femur compared to control knees (17.1% thicker, P = 0.014, W = 177). Cartilage differences were not detected (P > 0.05) in these regions. CONCLUSIONS: This study demonstrates that subchondral bone plate thickness differences are prominent following knee injury, as measured by HR-pQCT, but no statistically significant differences in cartilage morphology, measured by MRI, were found between ACLR knees compared to contralateral and control knees. These data provide novel insight into post-traumatic knee injuries that may be signs of early OA pathogenesis.


Subject(s)
Anterior Cruciate Ligament Reconstruction/adverse effects , Cartilage, Articular/diagnostic imaging , Cartilage, Articular/pathology , Imaging, Three-Dimensional/methods , Magnetic Resonance Imaging/methods , Tomography, X-Ray Computed/methods , Age Factors , Anterior Cruciate Ligament Injuries/complications , Anterior Cruciate Ligament Injuries/surgery , Anterior Cruciate Ligament Reconstruction/methods , Case-Control Studies , Female , Growth Plate/diagnostic imaging , Growth Plate/pathology , Humans , Image Interpretation, Computer-Assisted , Prognosis , Reference Values , Risk Assessment , Time Factors
3.
Prev Med ; 111: 225-230, 2018 06.
Article in English | MEDLINE | ID: mdl-29567438

ABSTRACT

This report explores intentional tanning behaviors among Canadian high school students in light of provincial restrictions on UV tanning device use among youth. Data are from the Cancer Risk Assessment in Youth Survey (CRAYS), collected from January to December 2015, at randomly selected high schools in 7 provinces. Relevant variables were: tanning methods ever used, demographics, and location and refusal of UV tanning device (beds, lamps) use in the past 12 months. Data were weighted so total survey weights by male/female, grade and province equal actual enrolments in these groups. Analyses were conducted in SAS, mostly for grades 10 and 11. Rao-Scott chi squared tests and p-values were calculated. Among 6803 grade 10 and 11 participants, 82% tanned intentionally, mostly by being/playing outside, or laying in the sun. Spray/self-tanners were used by 15% of participants. UV tanning device use was uncommon (4.4%), lowest in Ontario (2.7%) and British Columbia (3.8%), which have legislation against use among youth. Of 202 who used UV tanning devices in the past 12 months, most did at salons/studios (85%), 35% at home and 30% at a gym. Two hundred and forty-nine participants (3.4%) were refused use of UV tanning devices in the past 12 months. While legislation appears to deter UV tanning device use, it appears to have no impact on UV exposure among high school students overall. Greater prevention efforts are required to deter intentional tanning among high school students.


Subject(s)
Health Behavior , Skin Neoplasms/prevention & control , Students/statistics & numerical data , Sunbathing/statistics & numerical data , Ultraviolet Rays/adverse effects , Adolescent , Age Factors , Canada , Female , Health Knowledge, Attitudes, Practice , Humans , Male , Sex Factors , Surveys and Questionnaires
4.
Chronic Dis Inj Can ; 34(2-3): 121-31, 2014 Jul.
Article in English, French | MEDLINE | ID: mdl-24991775

ABSTRACT

INTRODUCTION: Understanding the characteristics of experimental smoking among youth is critical for designing prevention programs. This study examined which student- and school-level factors differentiated experimental smokers from never smokers in a nationally representative sample of Canadian students in grades 9 to 12. METHODS: School-level data from the 2006 Canadian Census and one built environment characteristic (tobacco retailer density) were linked with data from secondary school students from the 2008-2009 Canadian Youth Smoking Survey and examined using multilevel logistic regression analyses. RESULTS: Experimental smoking rates varied across schools (p < .001). The location (adjusted odds ratio [AOR] = 0.66, 95% CI: 0.49-0.89) of the school (urban vs. rural) was associated with the odds of a student being an experimental smoker versus a never smoker when adjusting for student characteristics. Students were more likely to be experimental smokers if they were in a lower grade, reported low school connectedness, used alcohol or marijuana, believed that smoking can help people relax, received pocket money each week and had a family member or close friend who smoked cigarettes. CONCLUSION: School-based tobacco prevention programs need to be grade-sensitive and comprehensive in scope; include strategies that can increase students' attachment to their school; and address multi-substance use, tobacco-related beliefs and the use of pocket money. These programs should also reach out to students who have smoking friends and family members. Schools located in rural settings may require additional resources.


TITRE: Les fumeurs à titre expérimental sont-ils différents de leurs camarades de classe n'ayant jamais fumé? Une analyse multiniveaux des jeunes Canadiens de la 9e à la 12e année. INTRODUCTION: Il est essentiel de comprendre les caractéristiques du tabagisme expérimental chez les jeunes pour élaborer des programmes de prévention. Dans cette étude, nous avons analysé, à partir d'un échantillon représentatif des élèves canadiens de la 9e à la 12e année, les facteurs relatifs aux élèves et les facteurs relatifs aux écoles qui différenciaient les fumeurs à titre expérimental des élèves n'ayant jamais fumé. MÉTHODOLOGIE: Des données relatives aux écoles recueillies dans le cadre du Recensement de 2006 ainsi qu'une caractéristique relative au milieu bâti (densité des détaillants de produits du tabac) ont été reliées à des données relatives aux élèves du secondaire tirées de l'Enquête sur le tabagisme chez les jeunes de 2008-2009 et ont été soumises à une série d'analyses par régression logistique multiniveaux. RÉSULTATS: Le taux de tabagisme expérimental variait d'une école à l'autre (p < 0,001). Après ajustement en fonction des caractéristiques des élèves, on a observé une association entre l'emplacement (rapport de cotes ajusté = 0,66, intervalle de confiance à 95 % : 0,49 à 0,89) de l'école (milieu urbain ou rural) et le risque qu'un élève soit fumeur à titre expérimental plutôt qu'élève n'ayant jamais fumé. Les élèves étaient plus susceptibles d'être fumeurs à titre expérimental s'ils étaient d'un niveau scolaire inférieur, s'ils avaient un faible sentiment d'appartenance à leur école, s'ils consommaient de l'alcool ou de la marijuana, s'ils croyaient que le tabagisme avait un effet apaisant, s'ils recevaient de l'argent de poche chaque semaine et si un membre de leur famille ou un de leurs amis intimes fumait des cigarettes. CONCLUSION: Les programmes de prévention du tabagisme en milieu scolaire doivent à la fois être adaptés au niveau scolaire et exhaustifs, comprendre des stratégies visant à accroître le sentiment d'appartenance des élèves à leur école et tenir compte du phénomène de polyconsommation, des croyances relatives au tabagisme et de l'utilisation qui est faite de l'argent de poche. Ces programmes devraient également cibler les élèves dont un ami ou un membre de la famille fume. Par ailleurs, les écoles situées en milieu rural pourraient avoir besoin de ressources supplémentaires.


Subject(s)
Adolescent Behavior/psychology , Health Knowledge, Attitudes, Practice , Smoking/epidemiology , Smoking/psychology , Tobacco Products/supply & distribution , Adolescent , Alcohol Drinking/epidemiology , Canada/epidemiology , Commerce/statistics & numerical data , Cross-Sectional Studies , Environment Design , Female , Friends , Health Surveys , Humans , Male , Marijuana Smoking/epidemiology , Nuclear Family , Organizational Policy , Risk Factors , Rural Population/statistics & numerical data , Schools/organization & administration , Smoking/legislation & jurisprudence , Social Environment , Tobacco Products/economics , Urban Population/statistics & numerical data
5.
Chronic Dis Inj Can ; 34(2-3): 154-62, 2014 Jul.
Article in English, French | MEDLINE | ID: mdl-24991778

ABSTRACT

INTRODUCTION: Youth Excel was a 3-year pan-Canadian initiative to advance youth health through improving knowledge development and exchange (KDE) capacity. KDE capacity refers to an improvement cycle linking evidence and action. Capacities include local surveillance of youth behaviours; knowledge exchange; skills, resources and a supportive environment to use knowledge; and evaluation. METHODS: Interviews were conducted with Youth Excel members, including 7 provincial teams and 2 national organizations. Interviews explored participant experiences with building KDE capacity. RESULTS: Local surveillance systems were considered the backbone to KDE capacity, strengthened by co-ordinating surveys within and across jurisdictions and using common indicators and measures. The most effective knowledge exchange included tailored products and opportunities for dialogue and action planning. Evaluation is the least developed KDE component. Building KDE capacity requires frequent dialogue, mutually beneficial partnerships and trust. It also requires attention to language, vision, strategic leadership and funding. CONCLUSION: Youth Excel reinforces the need for a KDE system to improve youth health that will require new perspectives and sustained commitment from individual champions and relevant organizations.


TITRE: Renforcement de la capacité de développement et d'échange des connaissances au Canada : leçons de Youth Excel. INTRODUCTION: Youth Excel est une initiative pancanadienne de 3 ans qui a eu comme objectif de favoriser la santé chez les jeunes par le biais de l'amélioration de la capacité de développement et d'échange des connaissances (DEC). La capacité de DEC repose sur un cycle d'amélioration reliant données probantes et interventions. Ses composantes étaient la surveillance locale des comportements des jeunes; l'échange de connaissances; les compétences, les ressources et l'environnement favorable pour l'utilisation des connaissances et enfin l'évaluation. MÉTHODOLOGIE: Nous avons réalisé des entrevues auprès de membres de Youth Excel relevant de sept équipes provinciales et de deux organisations nationales. Ces entrevues portaient sur les expériences des participants en lien avec le renforcement de la capacité de DEC. RÉSULTATS: L'élément central de la capacité de DEC était constitué par les systèmes de surveillance locale, renforcé par la coordination d'enquêtes au sein des administrations et entre administrations et par le recours à des indicateurs et à des mesures communes. Les échanges de connaissances les plus efficaces étaient ceux qui portaient sur des produits adaptés et qui mettaient à profit les occasions de dialogue et de planification des interventions. La capacité évaluative est demeurée la capacité de DEC la moins élaborée. Le renforcement de la capacité globale de DEC repose sur un dialogue fréquent, des partenariats mutuellement bénéfiques et de la confiance. Il exige également que l'on porte attention au langage, à la vision, au leadership stratégique et au financement. CONCLUSION: L'expérience de Youth Excel montre qu'il faut, pour renforcer un système de DEC qui améliore la santé des jeunes, explorer de nouvelles perspectives et obtenir un engagement soutenu de la part des champions ainsi que des organisations concernées.


Subject(s)
Adolescent Behavior , Capacity Building/organization & administration , Health Knowledge, Attitudes, Practice , Health Surveys/standards , Population Surveillance , Program Evaluation , Adolescent , Canada , Child , Communications Media , Cooperative Behavior , Diet , Health Surveys/methods , Humans , Information Dissemination , Interviews as Topic , Leadership , Motor Activity , Program Development , Qualitative Research , Smoking , Translational Research, Biomedical , Trust
6.
Bone ; 64: 263-72, 2014 Jul.
Article in English | MEDLINE | ID: mdl-24780879

ABSTRACT

In the current study, we used an estrogen-deficient mouse model of osteoporosis to test the efficacy of a cell-generated bone tissue construct for bone augmentation of an impaired healing fracture. A reduction in new bone formation at the defect site was observed in ovariectomized fractures compared to the control group using repeated measures in vivo micro-computed tomography (µCT) imaging over 4 weeks. A significant increase in the bone mineral density (BMD), trabecular bone volume ratio, and trabecular number, thickness and connectivity were associated with fracture repair in the control group, whereas the fractured bones of the ovariectomized mice exhibited a loss in all of these parameters (p<0.001). In a separate group, ovariectomized fractures were treated with murine embryonic stem (ES) cell-derived osteoblasts loaded in a three-dimensional collagen I gel and recovery of the bone at the defect site was observed. A significant increase in the trabecular bone volume ratio (p<0.001) and trabecular number (p<0.01) was observed by 4 weeks in the fractures treated with cell-loaded collagen matrix compared to those treated with collagen I alone. The stem cell-derived osteoblasts were identified at the fracture site at 4 weeks post-implantation through in situ hybridization histochemistry. Although this cell tracking method was effective, the formation of an ectopic cellular nodule adjacent to the knee joints of two mice suggested that alternative in vivo cell tracking methods should be employed in order to definitively assess migration of the implanted cells. To our knowledge, this study is the first of its kind to examine the efficacy of stem cell therapy for fracture repair in an osteoporosis-related fracture model in vivo. The findings presented provide novel insight into the use of stem cell therapies for bone injuries.


Subject(s)
Embryonic Stem Cells/cytology , Fracture Healing , Models, Animal , Pluripotent Stem Cells/cytology , Stem Cell Transplantation , Animals , In Situ Hybridization , Male , Mice , X-Ray Microtomography
7.
Chronic Dis Inj Can ; 33(4): 257-66, 2013 Sep.
Article in English, French | MEDLINE | ID: mdl-23987222

ABSTRACT

INTRODUCTION: The research teams undertook a case study design using a common analytical framework to investigate three provincial (Prince Edward Island, New Brunswick and Manitoba) knowledge exchange systems. These three knowledge exchange systems seek to generate and enhance the use of evidence in policy development, program planning and evaluation to improve youth health and chronic disease prevention. METHODS: We applied a case study design to explore the lessons learned, that is, key conditions or processes contributing to the development of knowledge exchange capacity, using a multi-data collection method to gain an in-depth understanding. Data management, synthesis and analysis activities were concurrent, iterative and ongoing. The lessons learned were organized into seven "clusters." RESULTS: Key findings demonstrated that knowledge exchange is a complex process requiring champions, collaborative partnerships, regional readiness and the adaptation of knowledge exchange to diverse stakeholders. DISCUSSION: Overall, knowledge exchange systems can increase the capacity to exchange and use evidence by moving beyond collecting and reporting data. Areas of influence included development of new partnerships, expanded knowledge-sharing activities, and refinement of policy and practice approaches related to youth health and chronic disease prevention.


TITRE: Étude sur les systèmes d'échange des connaissances pour la santé des jeunes et la prévention des maladies chroniques : étude de cas menée dans trois provinces. INTRODUCTION: Les équipes de recherche ont adopté un modèle d'étude de cas utilisant un cadre d'analyse commun dans le but d'étudier trois systèmes provinciaux (Île-du-Prince-Édouard, Nouveau-Brunswick et Manitoba) d'échange des connaissances. Ces trois systèmes visent à générer et utiliser des données probantes lors de l'élaboration des politiques, de la planification des programmes et des évaluations afin d'améliorer la santé des jeunes et de prévenir les maladies chroniques. MÉTHODOLOGIE: Nous avons appliqué un modèle d'étude de cas pour examiner en profondeur les leçons apprises (c.-à-d. les principales conditions ou les principaux processus contribuant au développement de la capacité d'échange des connaissances) à l'aide d'une méthode de collecte de données multiples. Les activités de gestion, de synthèse et d'analyse des données ont été simultanées, itératives et continues. Les leçons apprises ont été classées en sept catégories. RÉSULTATS: L'échange des connaissances est un processus complexe, qui exige des champions et des partenariats de collaboration, une adaptation aux divers intervenants et qui exige aussi que les régions soient préparées. ANALYSE: Dans l'ensemble, les systèmes d'échange des connaissances peuvent accroître la capacité d'échange et d'utilisation des données probantes en allant au-delà de la collecte et de la transmission de données. Leurs aires d'influence sont l'établissement de nouveaux partenariats, des activités élargies d'échange des connaissances et le perfectionnement des approches axées sur les politiques et les pratiques liées à la santé des jeunes et à la prévention des maladies chroniques.


Subject(s)
Chronic Disease/prevention & control , Health Promotion , Information Dissemination/methods , Knowledge Management , Program Development , Adolescent , Cooperative Behavior , Data Collection , Evidence-Based Medicine , Humans , Leadership , Manitoba , New Brunswick , Policy Making , Prince Edward Island , Public-Private Sector Partnerships
8.
Chronic Dis Inj Can ; 32(1): 47-54, 2011 Dec.
Article in English | MEDLINE | ID: mdl-22153176

ABSTRACT

This paper describes the survey development, design and data collection protocol for the 2008/2009 Youth Smoking Survey (YSS) and the changes to the YSS survey and protocols across the 5 survey cycles (1994, 2002, 2004/2005, 2006/2007, 2008/2009). Canada's Youth Smoking Survey is a nationally representative school-based survey of students (grades 6 to 12 in 2008/2009) from randomly sampled public and private schools in the ten provinces. The main objective of the YSS is to provide benchmark data on national smoking prevalence rates for youth. Key features of the 2008/2009 YSS include consistent measures across survey cycles, a survey team of researchers and non-governmental organizations, a link to school and student level measures, provision of tailored feedback reports to schools and publicly available datasets.


Subject(s)
Health Surveys/methods , Population Surveillance , Smoking/epidemiology , Surveys and Questionnaires , Adolescent , Canada/epidemiology , Humans , Prevalence , Schools
9.
Tob Control ; 18(6): 466-73, 2009 Dec.
Article in English | MEDLINE | ID: mdl-19797534

ABSTRACT

INTRODUCTION: Given that little is known about the price-related cigarette brand preferences of youths, the current study seeks to characterise cigarette brand preferences and examine factors associated with smoking discount or native cigarette brands among Canadian youths who are current smokers. METHODS: This study used nationally representative data collected from 71,003 grade 5-12 students as part of the 2006-7 Canadian Youth Smoking Survey (YSS). Using data from current smokers, logistic regression models were used to examine factors associated with smoking discount or native cigarette brands relative to premium cigarette brands. RESULTS: In 2006, premium cigarettes were the most prevalent brand of cigarette youths report usually smoking (49.4%); a substantial number of youths do report usually smoking either discount (12.9%) or native (9.3%) cigarette brands. Occasional smokers were more likely to report usually smoking premium cigarettes whereas daily smokers were more likely to report smoking either discount or native cigarettes. In particular, discount and native brands appear to be appealing among smoking youths with less spending money or those who are heavier smokers compared to youths smoking premium brands. CONCLUSION: Discount and native cigarette brands are commonly used by a substantial number of smoking youths in Canada. Additional research is required to better understand the reasons behind different cigarette brand preferences and how youths are able to access premium, discount and illicit native cigarettes. Moreover, ongoing surveillance of the cigarette brand preferences of youths is required for guiding future tobacco control policy and programming activities.


Subject(s)
Adolescent Behavior , Consumer Behavior/statistics & numerical data , Smoking/economics , Adolescent , Canada/epidemiology , Costs and Cost Analysis/statistics & numerical data , Female , Health Surveys , Humans , Male , Smoking/epidemiology
10.
Osteoporos Int ; 20(3): 445-53, 2009 Mar.
Article in English | MEDLINE | ID: mdl-18661091

ABSTRACT

UNLABELLED: We examined the contributions of femoral neck cortical and trabecular bone to proximal femur failure load. We found that trabecular bone mineral density explained a significant proportion of variance in failure load after accounting for total bone size and cortical bone mineral content or cortical area. INTRODUCTION: The relative contribution of femoral neck trabecular and cortical bone to proximal femur failure load is unclear. OBJECTIVES: Our primary objective was to determine whether trabecular bone mineral density (TbBMD) contributes to proximal femur failure load after accounting for total bone size and cortical bone content. Our secondary objective was to describe regional differences in the relationship among cortical bone, trabecular bone, and failure load within a cross-section of the femoral neck. MATERIALS AND METHODS: We imaged 36 human cadaveric proximal femora using quantitative computed tomography (QCT). We report total bone area (ToA), cortical area (CoA), cortical bone mineral content (CoBMC), and TbBMD measured in the femoral neck cross-section and eight 45 degrees regions. The femora were loaded to failure. RESULTS AND OBSERVATIONS: Trabecular bone mineral density explained a significant proportion of variance in failure load after accounting for ToA and then either CoBMC or CoA respectively. CoBMC contributed significantly to failure load in all regions of the femoral neck except the posterior region. TbBMD contributed significantly to failure load in all regions of the femoral neck except the inferoanterior, superoposterior, and the posterior regions. CONCLUSION: Both cortical and trabecular bone make significant contributions to failure load in ex vivo measures of bone strength.


Subject(s)
Bone Density/physiology , Femur Neck/physiology , Hip Fractures/pathology , Absorptiometry, Photon , Adult , Aged , Aged, 80 and over , Cadaver , Female , Femur Neck/anatomy & histology , Femur Neck/diagnostic imaging , Hip Fractures/diagnostic imaging , Humans , Male , Middle Aged , Stress, Mechanical , Tomography, X-Ray Computed
11.
Health Educ Res ; 23(1): 81-93, 2008 Feb.
Article in English | MEDLINE | ID: mdl-17301057

ABSTRACT

Although adolescents who overestimate peer smoking prevalence are more likely to smoke, little research has focused on the factors associated with why the majority of adolescents overestimate peer smoking rate. The purpose of this study was to examine demographic, social, environmental and behavioural characteristics related to overestimation of peer smoking prevalence among secondary school students. The current study analysed data collected in two Canadian studies that used the Tobacco Module of the School Health Action, Planning and Evaluation System, a school-based questionnaire. One study surveyed 23 458 students (Grades 9-13) in 29 schools during 2001-02, and the other surveyed 25 452 students in 39 schools in 2003. Results of multiple logistic regression indicate that grade, gender, close friends' smoking, seeing smoking at school, family members' smoking, smoking in the home and smoking status have a clear association with overestimation; school smoking rate and susceptibility to smoking show a tentative relationship and warrant further study. Other factors may also be important for prevalence estimation, and further research is needed to identify these factors. Since adolescents tend to overestimate peer smoking prevalence and perceived prevalence is in turn linked to smoking behaviour, interventions should focus on creating realistic perceptions of smoking prevalence.


Subject(s)
Peer Group , Smoking/epidemiology , Smoking/psychology , Adolescent , Age Factors , Family , Female , Humans , Male , Prevalence , Sex Factors , Social Environment , Socioeconomic Factors
12.
Osteoporos Int ; 18(7): 991-7, 2007 Jul.
Article in English | MEDLINE | ID: mdl-17268944

ABSTRACT

UNLABELLED: We studied the relations between bone geometry and density and the mechanical properties of human cadaveric tibiae. Bone geometry, assessed by MRI and pQCT, and bone density, assessed by DXA, were significantly associated with bone's mechanical properties. However, cortical density assessed by pQCT was not associated with mechanical properties. INTRODUCTION: The primary objective of this study was to determine the contribution of cross-sectional geometry (by MRI and pQCT) and density (by pQCT and DXA) to mechanical properties of the human cadaveric tibia. METHODS: We assessed 20 human cadaveric tibiae. Bone cross-sectional geometry variables (total area, cortical area, and section modulus) were measured with MRI and pQCT. Cortical density and areal BMD were measured with pQCT and DXA, respectively. The specimens were tested to failure in a four-point bending apparatus. Coefficients of determination between imaging variables of interest and mechanical properties were determined. RESULTS: Cross-sectional geometry measurements from MRI and pQCT were strongly correlated with bone mechanical properties (r(2) range from 0.55 to 0.85). Bone cross-sectional geometry measured by MRI explained a proportion of variance in mechanical properties similar to that explained by pQCT bone cross-sectional geometry measurements and DXA measurements. CONCLUSIONS: We found that there was a close association between geometry and mechanical properties regardless of the imaging modality (MRI or pQCT) used.


Subject(s)
Tibia/anatomy & histology , Tibia/physiology , Tibial Fractures/pathology , Tibial Fractures/physiopathology , Weight-Bearing/physiology , Absorptiometry, Photon , Aged , Aged, 80 and over , Cadaver , Diaphyses/anatomy & histology , Diaphyses/diagnostic imaging , Diaphyses/physiology , Female , Humans , Magnetic Resonance Imaging , Male , Models, Biological , Predictive Value of Tests , Tibia/diagnostic imaging , Tibial Fractures/diagnostic imaging
13.
Osteoporos Int ; 17(10): 1539-45, 2006 Oct.
Article in English | MEDLINE | ID: mdl-16847586

ABSTRACT

INTRODUCTION: Magnetic resonance imaging (MRI) is a promising medical imaging technique that we used to assess femoral neck cortical geometry. OBJECTIVES: Our primary objective was to assess whether cortical bone in the femoral neck assessed by MRI was associated with failure load in a simulated sideways fall, with and without adjustment for total bone size. Our secondary objective was to assess the reliability of the MRI measurements. MATERIALS AND METHODS: We imaged 34 human cadaveric proximal femora using MRI and dual-energy X-ray absorptiometry (DXA). MRI measurements of cross-sectional geometry at the femoral neck were the cortical cross-sectional area (CoCSA(MRI)), second area moment of inertia (x axis; Ix(MRI)), and section modulus (x axis; Zx(MRI)). DXA images were analyzed with the standard Hologic protocol. From DXA, we report the areal bone mineral density (aBMD(DXA)) in the femoral neck and trochanteric subregions of interest. The femora were loaded to failure at 100 mm/s in a sideways fall configuration (15 degrees internal rotation, 10 degrees adduction). RESULTS AND OBSERVATIONS: Failure load (N) was the primary outcome. We observed that the femoral neck CoCSA(MRI) and Ix(MRI) were strongly associated with failure load (r (2)=0.46 and 0.48, respectively). These associations were similar to those between femoral neck aBMD and failure load (r (2)=0.40), but lower than the associations between trochanteric aBMD and failure load (r (2)=0.70). CONCLUSION: We report that MRI holds considerable promise for measuring cortical bone geometry in the femoral neck and for predicting strength at the proximal femur.


Subject(s)
Femoral Fractures/pathology , Femur Neck/pathology , Absorptiometry, Photon/methods , Adult , Aged , Aged, 80 and over , Bone Density , Female , Femoral Fractures/physiopathology , Femur/physiopathology , Humans , Magnetic Resonance Imaging/methods , Male , Middle Aged , Reproducibility of Results , Stress, Mechanical
14.
Can J Public Health ; 92(6): 433-6, 2001.
Article in English | MEDLINE | ID: mdl-11799547

ABSTRACT

We conducted in-class written surveys of fourth to eighth grade children's eating and smoking behaviours in southwestern Ontario (n = 870) and Charlottetown (n = 423) in order to facilitate local school boards' and health units' planning of health education initiatives. Using chi-square analysis, we examined sex, grade, provincial and rural-urban differences in behaviours. No rural-urban differences emerged. While students reported few gender differences in food group consumption, more PEI students consumed French fries, snack foods, cakes and cookies, and regular soft drinks daily. Only 60.1% (379/630) of girls and 70.0% (462/660) of boys (chi 2 = 13.8; p < 0.001) ate breakfast every day, falling to 53.2% (115/216) among eighth grade girls, and 32.9% (25/76) among students who smoked. The prevalence of smoking was 4.8% (n = 40) in Ontario and 8.5% (n = 36) in PEI (chi 2 = 6.8; p < 0.01). Compared to non-smokers, a higher proportion of students who smoked consumed snack foods and regular soft drinks daily. The results emphasize the need to promote healthy eating behaviours and anti-smoking messages among school children.


Subject(s)
Feeding Behavior/psychology , Health Promotion , Smoking/psychology , Students/psychology , Adolescent , Adolescent Behavior , Canada , Child , Child Behavior , Data Collection , Female , Humans , Male , Schools
16.
Am J Public Health ; 89(12): 1827-31, 1999 Dec.
Article in English | MEDLINE | ID: mdl-10589310

ABSTRACT

OBJECTIVES: This study determined the effect of provider (nurse or teacher) and training method (workshop or self-preparation) on outcomes of a social influences smoking prevention program. METHODS: One hundred elementary schools were stratified by school risk score (high risk = high smoking rate among senior students) and assigned randomly to conditions: (1) teacher/self-preparation, (2) teacher/workshop, (3) nurse/self-preparation, (4) nurse/workshop, and (5) control. Intervention occurred in grades 6 to 8. Smoking status at the end of grade 8 was the primary endpoint variable. RESULTS: Intervention reduced grade 8 smoking rates in high-risk schools (smoking rates of 26.9% in control vs 16.0% in intervention schools) but not in low-risk schools. There were no significant differences in outcome as a function of training method and no significant differences in outcome between teacher-provided and nurse-provided interventions in high- and medium-risk schools. Although nurses achieved better outcomes than did teachers in low-risk schools, neither provider type achieved outcomes superior to the control condition in those schools. CONCLUSIONS: Workshop training did not affect outcomes. Teachers and nurses were equally effective providers. Results suggest that programming should target high-risk schools.


Subject(s)
Health Promotion/methods , School Health Services , Smoking Prevention , Social Environment , Adolescent , Faculty , Female , Humans , Male , Ontario/epidemiology , Outcome Assessment, Health Care , Risk , School Nursing , Smoking/epidemiology
17.
Cancer Prev Control ; 1(3): 196-212, 1997 Aug.
Article in English | MEDLINE | ID: mdl-9765745

ABSTRACT

Within the context of a framework for cancer control, this article reviews evidence and suggests research directions for 3 types of school-based smoking interventions: elementary school prevention, secondary school interventions and interventions linking community and school. Directions for smoking research in elementary schools include improving adoption through the provision of effectiveness criteria, tailoring interventions to schools and training. Monitoring at micro and macro levels may help planning and implementation, but clearer evidence is required of its feasibility. Fundamental research should explore new options to understand why youth do not start smoking. Smoking intervention research at the secondary school level is less well established, with only 1 effectiveness trial reported. We recommend testing models that involve youth in developing their own solutions and examining the interaction of various control measures. Sustainability issues have led researchers to embed school-based smoking interventions in community-wide activities. Intervention research of this sort still needs to determine how to apply approaches (e.g., comprehensive school health) and what the appropriate roles are (such as technical assistance) for community agencies. All research using these school-community approaches needs to include process measures to explain potential failures to obtain significant differences between components. In addition, we call for research on the training of educators and health personnel, to increase the priority given to smoking prevention and improve the implementation of existing programs. Research on policy initiatives that lead to effective training needs to be explored. Finally, we argue that application of the principles incorporated into the cancer control framework (e.g., through participatory research methods) strengthens the research process and results.


Subject(s)
Neoplasms/prevention & control , School Health Services , Smoking Prevention , Adolescent , Attitude to Health , Child , Community Health Services , Community Participation , Comprehensive Health Care , Feasibility Studies , Female , Health Behavior , Health Plan Implementation , Health Planning , Health Policy , Health Priorities , Humans , Male , Process Assessment, Health Care , Research , Smoking/psychology
18.
Cancer Prev Control ; 1(5): 361-5, 1997 Dec.
Article in English | MEDLINE | ID: mdl-9765758

ABSTRACT

This paper offers a critique of the National Cancer Institute of Canada's (NCIC) framework for cancer control. The critique has been prepared by researchers who used the framework to review the literature in 5 substantive areas. These reviews, published in the current and previous issues of CPC, were designed to begin to outline a research agenda for the Sociobehavioural Cancer Research Network. In this paper, the authors reflect on the strengths and limitations of the framework. Perceived strengths are that the framework (a) facilitates systematic thinking about research options and priorities, (b) helps foster clear communication, (c) links science and practice, (d) may assist grant review panels to place proposed studies in context and (e) emphasizes important values. Perceived concerns include the following: (a) potential users are not familiar with the framework, (b) lack of clarity of definitions and classification criteria, (c) the utility of the framework is not immediately self-evident to potential users, (d) the framework lacks emphasis on environmental and policy interventions and (e) it is not clear how the values espoused are to be integrated with other dimensions of the framework. The concerns were seen as remediable. In short, the framework was seen to be valuable in its current form; refinement may enhance its value.


Subject(s)
Neoplasms/prevention & control , Canada , Humans
20.
Can Fam Physician ; 29: 543-50, 1983 Mar.
Article in English | MEDLINE | ID: mdl-21283350

ABSTRACT

Obesity is a common condition which has important effects on health status and longevity. This review examines the efficacy of treatments for both moderate and severe obesity. A plan of treatment combining diet, exercise, and behavioral strategies is outlined. Surgery and its complications are reviewed. Eight management issues, including rate of weight loss, self-help groups, and fringe therapies, are presented. Management recommendations are based on a critical review of the weight loss literature.

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