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Ka K.,McGill University | Ka K.,INRS Armand Frappier Institute | Rousseau M.-C.,McGill University | Rousseau M.-C.,INRS Armand Frappier Institute | And 5 more authors.
Journal of Clinical Periodontology | Year: 2014

Background Osteocalcin, a protein secreted by osteoblasts during bone formation, is negatively associated with adult periodontal disease. Little is known about this association in children. Aim To examine the extent to which plasma undercarboxylated osteocalcin (ucOC) is associated with gingival crevicular fluid tumour necrosis factor-Alpha (GCF TNF-α) - a potential marker of gingival inflammation - in children. Methods We used data from the Quebec Adipose and Lifestyle InvesTigation in Youth cohort, an ongoing longitudinal study on the natural history of obesity among Caucasian children with a family history of obesity in Quebec, Canada. This cross-sectional analysis from the baseline visit includes 120 children aged 8-10 years. Plasma ucOC and GCF TNF-α levels were determined by enzyme-linked immunosorbent assay. Linear regression analyses, adjusting for age, gender, family income, sexual maturity stage, daily physical activity, obesity, and fasting glucose were conducted, with TNF-α level as the dependent variable. Results A 1-ng/ml increase in ucOC was associated with a 0.96% decrease (95% confidence interval (CI): -1.69, -0.23) in GCF TNF-α level. Conclusion A negative association between a marker of bone formation and a marker of gingival inflammation was observed as early as childhood among Caucasian children with a family history of obesity. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd. Source


Ka K.,McGill University | Ka K.,INRS Armand Frappier Institute | Rousseau M.-C.,McGill University | Rousseau M.-C.,INRS Armand Frappier Institute | And 6 more authors.
Hormone Research in Paediatrics | Year: 2013

Background/Aims: Childhood and adolescence are critical periods for bone growth. The independent association between lean and fat mass and indicators of bone health in children is not yet known. We aim to examine the association between each of lean and fat mass and indicators of bone health in 8- to 10-year-old prepubertal Caucasian children. Methods: We present a cross-sectional analysis of baseline data from the QUebec Adipose and Lifestyle InvesTigation in Youth (QUALITY) cohort which study the natural history of obesity. Study participants (n = 483) included prepubertal children aged 8-10 years and their biological parents. Whole-body bone mineral content (BMC, g), bone area (cm2), bone mineral density (BMD, g/cm2), lean mass (kg), and fat mass (kg) were measured by dual-energy X-ray absorptiometry. Data analyses include multiple linear regressions adjusted for potential confounding variables. Results: A 1-kg increase in lean mass was associated with 28.42 g, 19.88 cm2, and 0.007 g/cm2 increase in whole-body BMC, bone area and BMD respectively. A 1-kg increase in fat mass was associated with 9.32 g, 8.02 cm2, and 0.002 g/cm2 increase in whole-body BMC, bone area and BMD, respectively. Conclusion: Increasing lean mass in children may help optimize bone acquisition and prevent future osteoporosis. © 2013 S. Karger AG, Basel. Source


Douvile M.,Environment Canada | Gagne F.,Environment Canada | Zhu B.,Environment Canada | Fortier M.,INRS Armand Frappier Institute | Fournier M.,INRS Armand Frappier Institute
Research Journal of Biotechnology | Year: 2010

The increasing commercial applications of microbial products and consortia have raised concerns about their release to the environment and the potential for toxic effects on aquatic biota. This study characterized 25 bacteria, one yeast and one fungus using a combination of random amplified polymorphic DNA and 19 hydwlytic enzyme activities, with the purpose of determining their occurrence and potential effects on the immune systems of mussels exposed to a primary.-treated municipal effluent for seven weeks. The amplification product (552-bp) of cpn60 gene by using universal primers was sequenced for each micro-organism and available in GenBank. The microbial community structures in the digestive gland of mussels were also characterized using 16s ribosomal gene analysis by denaturing gradient gel electrophoresis (DGGE). The results revealed that each micro-organism was easily cultivated with usual growth media and the enzyme activity profiles permitted to propose an identification method using hierarchical tree and backpropagation neural networks classifications. The bacterial community structure based on DGGE of 16S rDNA in mussels changed with the concentration of the municipal effluent. This was also revealed by a characteristic change in enzyme activity profiles with increased frequency in acid and amide phosphatase, leucine aminopeptidase and ß-galactosidase in the isolated heterotrophic colonies in mussels. The analysis of heterotrophic bacteria colonies in unexposed mussels revealed that most colonies (6/10) were of unkown origin and only three bacterial colonies shared close similarities with B. subtilisis 11685, E. aerogenes, P. putida 12633. In mussels exposed to the municipal effluents, about half of the colonies were classified as unknowns while the other half was composed of bacteria showing close similarites with E. aerogenes, P. putida 12633 and 31800. These bacteria differed from those found in forming biofilms which was mainly associated to B. subtil is J J 685 or P. fluorescens 13525 functional properties. The immune system of the mussels was also compromised with decreased hemocyte density, increased phagocytosis activity and cytotoxic activity. While no trend between phagocytosis activity and the enzyme activity profiles was found, the increased frequency in leucine aminopeptidase and acid phosphatase were negatively correlated with the hemocyte density and cytotoxic activity. In conclusion, a methodology to track for the occurrence, bioavailability and potential immunotoxic effects of commercial microorganisms is proposed based on a combination of genetic and phenotypic (enzyme activity) markers and immunocompetent assessment. Preliminary results indicate mussels contained only three bacteria out of 25 bacteria that bear high functional similarity and the characteristic pertubations with the enzyme activity profiles were associated with immunocompetence changes. Source

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