Activity-independent targeting of mTOR to lysosomes in primary osteoclasts.

Mammalian target of rapamycin (mTOR) is activated by numerous stimuli, including amino acids and growth factors. This kinase is part of the mTOR complex 1 (mTORC1) which regulates cell proliferation, differentiation, and autophagy. Active mTORC1 is located on lysosomes and has been reported to disassociate from the lysosomal surface in the absence of amino acids.

Lysosomal pH Plays a Key Role in Regulation of mTOR Activity in Osteoclasts.

Mammalian target of rapamycin (mTOR) is a serine/threonine kinase involved in the regulation of cell growth. It has been shown to play an important role in osteoclast differentiation, particularly at the earlier stages of osteoclastogenesis. mTOR activation and function, as part of mTORC1 complex, is dependent on lysosomal localization and the vacuolar H(+) -ATPase (V-ATPase) activity; however, the precise mechanism is still not well understood.

Restaurant menu labelling: Is it worth adding sodium to the label?

Objective: Several provincial and federal bills have recommended various forms of menu labelling that would require information beyond just calories; however, the additional benefit of including sodium information is unknown. The objective of this study was to determine whether sodium information on menus helps consumers make lower-sodium choices and to understand what other factors influence the effect of menu labelling on consumers' meal choices.

Methods: A total of 3,080 Canadian consumers completed an online survey that included a repeated measures experiment in which consumers were asked to select what they would typically order from four mock-restaurant menus.

Increased statistical power with combined independent randomization tests used with multiple-baseline design.

Objectives: Physicians often assess the effectiveness of treatments on a small number of patients. Multiple-baseline designs (MBDs), based on the Wampold-Worsham (WW) method of randomization and applied to four subjects, have relatively low power. Our objective was to propose another approach with greater power that does not suffer from the time requirements of the WW method applied to a greater number of subjects.

Effects of vitamin E on bone turnover markers among US postmenopausal women.

Increased oxidative stress and inflammation resulting from aging and declining estrogen levels can lead to increased bone loss in postmenopausal women. Alpha-tocopherol and gamma-tocopherol, the two predominant isomers of vitamin E, have antioxidant and anti-inflammatory properties, but their effects on bone metabolism have not been well studied in humans. We examined the associations between dietary and total (diet and supplements) alpha-tocopherol intake, serum alpha-tocopherol and gamma-tocopherol levels and their ratio, and bone turnover markers (BTMs) among postmenopausal women aged ≥45 years.

Divergent body mass index trajectories between Aboriginal and non-Aboriginal Canadians 1994-2009--an exploration of age, period, and cohort effects.

Objectives: Aboriginal Canadians have a high burden of obesity and obesity-related chronic conditions. Body mass index (BMI) trajectories from 1994 to 2009 were estimated for Aboriginal and non-Aboriginal Canadians using self-reported height and weight data from the National Population Health Survey to explore age, period, and cohort effects of BMI change.

Methods: Linear growth curve models were estimated for 311 Aboriginal and 10,967 non-Aboriginal respondents divided into five birth cohorts born in the 1940s, 50s, 60s, 70s, and 80s.

Socio-economic patterns of obesity among aboriginal and non-Aboriginal Canadians.

Objectives: Large disparities exist between Aboriginal and non-Aboriginal Canadians in both obesity and socio-economic status (SES). The purpose of this paper was to assess associations between obesity and three indicators of SES - employment, education and income - in conjunction with demographic and lifestyle factors.

Methods: Using the nationally-representative Canadian Community Health Survey (CCHS) cycle 2.

Genetic variation in TAS1R2 (Ile191Val) is associated with consumption of sugars in overweight and obese individuals in 2 distinct populations.

Background: Taste is an important determinant of food consumption, and genetic variations in the sweet taste receptor subunit TAS1R2 may contribute to interindividual variations in sugar consumption.

Objective: We determined whether Ser9Cys and Ile191Val variations in TAS1R2 were associated with differences in the consumption of sugars in 2 populations.

Design: Population 1 included 1037 diabetes-free young adults in whom we assessed dietary intake by using a 1-mo, 196-item food-frequency questionnaire.

Associations of television viewing, physical activity and dietary behaviours with obesity in aboriginal and non-aboriginal Canadian youth.

Objective: To determine associations of diet, physical activity and television (TV) viewing time with obesity among aboriginal and non-aboriginal youth in conjunction with socio-economic variables.

Design: Cross-sectional study of differences between aboriginal and non-aboriginal groups and associations between lifestyle and socio-economic factors with obesity were examined.

Setting: Population data from the Canadian Community Health Survey Cycle 2.

A pure likelihood approach to the analysis of genetic association data: an alternative to Bayesian and frequentist analysis.

Investigators performing genetic association studies grapple with how to measure strength of association evidence, choose sample size, and adjust for multiple testing. We apply the evidential paradigm (EP) to genetic association studies, highlighting its strengths. The EP uses likelihood ratios (LRs), as opposed to P-values or Bayes' factors, to measure strength of association evidence.

Dopamine D2 receptor genotype (C957T) and habitual consumption of sugars in a free-living population of men and women.

Background/aims: The dopamine D2 receptor (DRD2) has been implicated in modulating the rewarding effects of foods high in sugar. The purpose of this study was to determine whether a variation in the DRD2 gene affects habitual consumption of sugars in a free-living population.

Methods: Caucasian men (n = 96) and women (n = 217) 20-29 years of age completed a 1-month food frequency questionnaire and were genotyped for the C957T polymorphism in the DRD2 gene.

Vitamin C deficiency in a population of young Canadian adults.

A cross-sectional study of the 979 nonsmoking women and men aged 20-29 years who participated in the Toronto Nutrigenomics and Health Study from 2004 to 2008 was conducted to determine the prevalence of serum ascorbic acid (vitamin C) deficiency and its association with markers of chronic disease in a population of young Canadian adults. High performance liquid chromatography was used to determine serum ascorbic acid concentrations from overnight fasting blood samples. A 1-month, 196-item food frequency questionnaire was used to assess dietary intakes.

NF-kappaB -94Ins/Del ATTG polymorphism modifies the association between dietary polyunsaturated fatty acids and HDL-cholesterol in two distinct populations.

We previously showed that polymorphisms in the tumor necrosis factor (TNF)-alpha gene, which is regulated by nuclear factor kappa B (NF-kappaB), modify the association between dietary polyunsaturated fatty acid (PUFA) intake and circulating HDL-cholesterol. Our objective was to determine whether a common polymorphism in the NFKB1 gene (-94Ins/Del ATTG) interacts with PUFA intake to affect HDL-cholesterol in two distinct populations. Participants were diabetes-free young adults (n=593) and older individuals with diet-treated type 2 diabetes (n=103).

Genetic polymorphisms of tumor necrosis factor-alpha modify the association between dietary polyunsaturated fatty acids and fasting HDL-cholesterol and apo A-I concentrations.

Background: Heterogeneity in circulating lipid concentrations in response to dietary polyunsaturated fatty acids (PUFAs) may be due, in part, to genetic variations. Tumor necrosis factor-alpha (TNF-alpha) is a proinflammatory cytokine that can induce hyperlipidemia and is known to be modulated by dietary PUFAs.

Objective: The objective was to determine whether TNF-alpha genotypes modify the association between dietary PUFA intake and serum lipid concentrations.

Pesticide exposures in professional turf applicators, job titles, and tasks performed: implications of exposure measurement error for epidemiologic study design and interpretation of results.

Background: Little information on the validity of job title and task classifications, for the prediction of pesticide use or exposure, is available.

Methods: Job titles and task classifications were evaluated in relation to the absorbed dose of herbicides in 98 professional turf applicators. Self-reported use over a 1-week period and other proxies of pesticide use were compared with employer records.

Risk of stroke in women exposed to low-dose oral contraceptives: a critical evaluation of the evidence.

Background: Use of the oral contraceptive pill (OCP) has been reported to be associated with stroke. With current OCPs containing less than 50 micro g of ethinyl estradiol, and many earlier studies reporting the association between OCPs and stroke, subjected to biases, we determined whether such an association exists and, if so, the magnitude of the risk.

Methods: Two independent searches were conducted to obtain relevant articles from MEDLINE, EMBASE, and Science Citation (1970 to June 2000).

A cohort study of dietary fibre intake and menarche.

Objective: To evaluate the influence of dietary fibre on menarche in a cohort of pre-menarcheal girls.

Design: Prospective cohort study.

Setting: Ontario, Canada.

Soluble fiber intake at a dose approved by the US Food and Drug Administration for a claim of health benefits: serum lipid risk factors for cardiovascular disease assessed in a randomized controlled crossover trial.

Background: The US Food and Drug Administration (FDA) approved health claims for 2 dietary fibers, beta-glucan (0.75 g/serving) and psyllium (1.78 g/serving), on the assumption that 4 servings/d would reduce cardiovascular disease risk.

Development of models to predict dose of pesticides in professional turf applicators.

Epidemiologic studies designed to assess the chronic effects of pesticides are limited by inadequate measurements of exposures. Although cohort studies have been initiated to evaluate the effects of 2,4-dichlorophenoxyacetic acid (2,4-D) and other pesticides in professional turf applicators, they may have limited power to detect significant health risks and may be subject to bias from exposure measurement error. In this study, the doses of 2,4-D, mecoprop [2-(4-chloro-2 methylphenoxy) propionic acid, MCPP] and dicamba (3,6-dichloro-o-anisic acid) were evaluated in a group of 98 professional turf applicators from 20 companies across southwestern Ontario.