241 resultados para Bone composition
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La première partie de cette recherche, consistant en une revue critique de la littérature, a mis en évidence le manque de connaissances relatives au phénomène de coupage des produits stupéfiants, la cocaïne et l'héroïne en particulier (Broséus et al., 2014). La seconde partie s'attelle alors à améliorer l'état des connaissances sur le phénomène de coupage des produits stupéfiants et, pour ce faire, se base sur les résultats d'analyses d'environ 6000 spécimens de cocaïne et 3000 d'héroïne saisis en Suisse ent 2006 et 2013. Le type de produits de coupage détectés (adultérant ou diluant) avec leurs fréquences d'apparition respectives, le degré de coupage des spécimens et finalement les niveaux de la chaine de distribution auxquels se produirait le coupage ont été tout particulièrement investigués. L'ensemble des renseignements obtenus permettent de mieux comprendre le marché de distribution et de consommation des produits stupéfiants et s'avèrent utiles pour la mise en place de politiques efficaces, que ce soit dans le cadre de démarches de prévention, de réduction des risques ou de dépression.
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Summary For the nutritional management of bone health and the prevention of osteoporosis it is important to identify nutrients that positively influence the bone remodeling process at the cellular level. Soy isoflavones show promising osteoprotective effects in animals and humans but their mechanism of action in bone cells is yet poorly understood. Firstly, soy tissue cultures were characterized as a new and optimized source of isoflavones. A large variability in the isoflavone content was observed and high-producing strains (46.3 mg/g dry wt isoflavones) were identified. In the Ishikawa cells bioassay, the estrogenicity of isoflavones was confirmed to be 1000 to 10000 less than 17Mestradiol and that of the malonyl forms was shown for the first time (EC50 of 350 nM and 1880 nM for malonylgenistin and malonyldaidzin, respectively). The estrogenic activity of soya tissue culture extracts correlated to their isoflavone content. Secondly, the effects of phytonutrients on BMP-2 gene expression and on the mevalonate synthesis pathway, as key mediators of bone formation, were investigated. Dietary achievable concentrations of genistein and daidzein (10vM), and statins (4xM) but not 17M estradiol (10nM), induced BMP-2 gene expression (by up to 3-fold) and inhibited the cholesterol biosynthetic pathway (by up to 50%) in the human osteoblastic cell line hP0B¬tert. In addition, several plant extracts (Cyperus rotundus, Lindera benzoin and Cnidium monnieri) induced BMP-2 gene expression but this induction was not restricted to the inhibition of the cholesterol synthesis pathway neither to the estrogenicity. Finally, the gene expression profiles during hP0B-tert differentiation induced by vitamin D and dexamethasone were analyzed with the Affymetrix human GeneChip. 1665 different genes and 98 ESTs were significantly regulated. The expression profiles of bone-related genes was largely in agreement with previously documented patterns, supporting the physiological relevance of the genomic results and the hP0B-tert cell line as a valid model of human osteoblast differentiation. The expression of alternative differentiation markers during the osteogenic treatment of hP0B-tert cells indicated that the adipocyte and myoblast differentiation pathways were repressed, confirming that these culture conditions allowed only osteoblast differentiation. The gene ontology analysis identified further sub-groups of genes that may be involved in the bone formation process. Aims of the thesis In order to define new strategies for the nutritional management of bone health and for the prevention of osteoporosis the major goal of the present work was to investigate the potential of phytonutrients to positively modulate the bone formation process at the cellular level and, in particular: 1.To select and optimise alternative plant sources containing high levels of isoflavones with estrogenic activity (Chapter 3). 2.To compare the effects of statins and phytonutrients on BMP-2 gene expression and on the mevalonate synthesis pathway and to select new plant extracts with a bone anabolic potential (Chapter 4). 3.To further characterize the new human periosteal cell line, hP0B-tert, as a bone- formation model, by elucidating its gene expression profile during differentiation induced by vitamin D and dexamethasone (Chapter 5).
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Introduction: Osteoporosis (OP) is a systemic skeletal disease characterized by a low bone mineral density (BMD) and a micro-architectural (MA) deterioration. Clinical risk factors (CRF) are often used as a MA approximation. MA is yet evaluable in daily practice by the Trabecular Bone Score (TBS) measure. TBS is a novel grey-level texture measurement reflecting bone micro-architecture based on the use of experimental variograms of 2D projection images. TBS is very simple to obtain, by reanalyzing a lumbar DXA-scan. TBS has proven to have diagnosis and prognosis value, partially independent of CRF and BMD. The aim of the OsteoLaus cohort is to combine in daily practice the CRF and the information given by DXA (BMD, TBS and vertebral fracture assessment (VFA)) to better identify women at high fracture risk. Method: The OsteoLaus cohort (1400 women 50 to 80 years living in Lausanne, Switzerland) started in 2010. This study is derived from the cohort COLAUS who started in Lausanne in 2003. The main goals of COLAUS is to obtain information on the epidemiology and genetic determinants of cardiovascular risk in 6700 men and women. CRF for OP, bone ultrasound of the heel, lumbar spine and hip BMD, VFA by DXA and MA evaluation by TBS are recorded in OsteoLaus. Preliminary results are reported. Results: We included 631 women: mean age 67.4±6.7 y, BMI 26.1±4.6, mean lumbar spine BMD 0.943±0.168 (T-score -1.4 SD), TBS 1.271±0.103. As expected, correlation between BMD and site matched TBS is low (r2=0.16). Prevalence of VFx grade 2/3, major OP Fx and all OP Fx is 8.4%, 17.0% and 26.0% respectively. Age- and BMI-adjusted ORs (per SD decrease) are 1.8 (1.2- 2.5), 1.6 (1.2-2.1), 1.3 (1.1-1.6) for BMD for the different categories of fractures and 2.0 (1.4-3.0), 1.9 (1.4-2.5), 1.4 (1.1-1.7) for TBS respectively. Only 32 to 37% of women with OP Fx have a BMD < -2.5 SD or a TBS < 1.200. If we combine a BMD < -2.5 SD or a TBS < 1.200, 54 to 60% of women with an osteoporotic Fx are identified. Conclusion: As in the already published studies, these preliminary results confirm the partial independence between BMD and TBS. More importantly, a combination of TBS subsequent to BMD increases significantly the identification of women with prevalent OP Fx which would have been miss-classified by BMD alone. For the first time we are able to have complementary information about fracture (VFA), density (BMD), micro- and macro architecture (TBS & HAS) from a simple, low ionizing radiation and cheap device: DXA. Such complementary information is very useful for the patient in the daily practice and moreover will likely have an impact on cost effectiveness analysis.
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OBJECTIVE: Prospective studies have shown that quantitative ultrasound (QUS) techniques predict the risk of fracture of the proximal femur with similar standardised risk ratios to dual-energy x-ray absorptiometry (DXA). Few studies have investigated these devices for the prediction of vertebral fractures. The Basel Osteoporosis Study (BOS) is a population-based prospective study to assess the performance of QUS devices and DXA in predicting incident vertebral fractures. METHODS: 432 women aged 60-80 years were followed-up for 3 years. Incident vertebral fractures were assessed radiologically. Bone measurements using DXA (spine and hip) and QUS measurements (calcaneus and proximal phalanges) were performed. Measurements were assessed for their value in predicting incident vertebral fractures using logistic regression. RESULTS: QUS measurements at the calcaneus and DXA measurements discriminated between women with and without incident vertebral fracture, (20% height reduction). The relative risks (RRs) for vertebral fracture, adjusted for age, were 2.3 for the Stiffness Index (SI) and 2.8 for the Quantitative Ultrasound Index (QUI) at the calcaneus and 2.0 for bone mineral density at the lumbar spine. The predictive value (AUC (95% CI)) of QUS measurements at the calcaneus remained highly significant (0.70 for SI, 0.72 for the QUI, and 0.67 for DXA at the lumbar spine) even after adjustment for other confounding variables. CONCLUSIONS: QUS of the calcaneus and bone mineral density measurements were shown to be significant predictors of incident vertebral fracture. The RRs for QUS measurements at the calcaneus are of similar magnitude as for DXA measurements.
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OBJECTIVE: Both subclinical hypothyroidism and the metabolic syndrome have been associated with increased risk of coronary heart disease events. It is unknown whether the prevalence and incidence of metabolic syndrome is higher as TSH levels increase, or in individuals with subclinical hypothyroidism. We sought to determine the association between thyroid function and the prevalence and incidence of the metabolic syndrome in a cohort of older adults. DESIGN: Data were analysed from the Health, Ageing and Body Composition Study, a prospective cohort of 3075 community-dwelling US adults. PARTICIPANTS: Two thousand one hundred and nineteen participants with measured TSH and data on metabolic syndrome components were included in the analysis. MEASUREMENTS: TSH was measured by immunoassay. Metabolic syndrome was defined per revised ATP III criteria. RESULTS: At baseline, 684 participants met criteria for metabolic syndrome. At 6-year follow-up, incident metabolic syndrome developed in 239 individuals. In fully adjusted models, each unit increase in TSH was associated with a 3% increase in the odds of prevalent metabolic syndrome (OR, 1.03; 95% CI, 1.01-1.06; P = 0.02), and the association was stronger for TSH within the normal range (OR, 1.16; 95% CI, 1.03-1.30; P = 0.02). Subclinical hypothyroidism with a TSH > 10 mIU/l was significantly associated with increased odds of prevalent metabolic syndrome (OR, 2.3; 95% CI, 1.0-5.0; P = 0.04); the odds of incident MetS was similar (OR 2.2), but the confidence interval was wide (0.6-7.5). CONCLUSIONS: Higher TSH levels and subclinical hypothyroidism with a TSH > 10 mIU/l are associated with increased odds of prevalent but not incident metabolic syndrome.
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OBJECTIVE: To see whether a fat-rich (50%) evening meal promoted fat oxidation and a different spontaneous food intake on the following day at breakfast than a meal with a lower fat content (20%) in 10 prepubertal obese girls. RESEARCH METHODS AND PROCEDURES: The postabsorptive and postprandial (10.5 hours) energy expenditure after a low-fat (LF) (20% fat, 68% carbohydrate, 12% protein) and an isocaloric (2.1 MJ) and isoproteic high-fat (HF; 50% fat, 38% carbohydrate, 12% protein) meal were measured by indirect calorimetry. RESULTS: Fat oxidation was not significantly different after the two meals [LF, 31 +/- 9 vs. HF, 35 +/- 9 g/10.5 hours, p = not significant (NS)]. The girls oxidized 1.8 +/- 0.9 times more fat than that ingested (11.1 grams) with the LF meal vs. 0.3 +/- 0.3 times more fat than that ingested (27.1 grams) with the HF meal (p < 0.001). Carbohydrate oxidation was significantly higher after an LF than an HF meal (39 +/- 12 vs. 29 +/- 9 g/10.5 hours, p < 0,05). At breakfast, the girls spontaneously ingested a similar amount of energy (1.5 +/- 0.7 vs. 1.5 +/- 0.6 MJ, p = NS) and macronutrient proportions (fat, 23% vs. 26%, p = NS; protein, 9% vs. 10%; carbohydrate, 68% vs. 64%,) independently of their having eaten an HF or an LF dinner. DISCUSSION: An HF dinner did not stimulate fat oxidation, and no compensatory effect in spontaneous food intake was observed during breakfast the following morning. Cumulated total fat oxidation after dinner was higher than total fat ingested at dinner, but a much larger negative fat balance was observed after the LF meal. Spontaneous energy and nutrient intakes at breakfast were similar after LF and HF isocaloric, isoproteic dinners. This study points out the lack of sensitivity of short-term fat balance to subsequently readjust fat intake and emphasizes the importance of an LF meal to avoid transient positive fat imbalance.
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Historically, it has been difficult to monitor the acute impact of anticancer therapies on hematopoietic organs on a whole-body scale. Deeper understanding of the effect of treatments on bone marrow would be of great potential value in the rational design of intensive treatment regimens. 3'-deoxy-3'-(18)F-fluorothymidine ((18)F-FLT) is a functional radiotracer used to study cellular proliferation. It is trapped in cells in proportion to thymidine-kinase 1 enzyme expression, which is upregulated during DNA synthesis. This study investigates the potential of (18)F-FLT to monitor acute effects of chemotherapy on cellular proliferation and its recovery in bone marrow, spleen, and liver during treatment with 2 different chemotherapy regimens.
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Bone loss secondary to inflammatory bowel diseases (IBD) is largely explained by activated T cells producing cytokines that trigger osteoclastogenesis and accelerate bone resorptionwhile inhibiting bone formation. In IBD, elevated expression of interleukin (IL)-15, a T cell growth factor, plays a central role in T cell activation, pro-inflammatory cytokine production and the development of colitis. We previously reported that IL-15 enhances RANKL-induced osteoclastogenesis and that an IL-15 antagonist, CRB-15, prevents weight and bone loss in a mousemodel of dextran sulfate sodium-induced colitis.We hypothesized that inhibition of IL-15 signalingmight prevent bone loss in IL-10 deficient (IL10−/−) mice, that develop spontaneous bowel inflammation associatedwith osteopeniawhen they are no longer raised under germ-free conditions.Mice received anIL-15 antagonist (CRB-15, 5 μg/day, n=5) or IgG2a (5 μg/day, n=4) fromweek 10 to 14 of age. The severity of colitis was assessed by histology and bowel cytokine gene expression by real time PCR. Bone mass and architecturewere evaluated by ex vivo DXA on femur and micro-computed tomography on femur and vertebra. Bodyweight gainwas similar in the two groups. After 4 weeks, colonwas 29% shorter in CRB-15 treatedmice (p<0.006), a sign of reduced inflammation. Histological analysis indicated a transmural infiltration of inflammatory cells, lymphoepithelial lesions and increased size of villi (histological score=4/6) in IgG2a treated mice, whereas colon from CRB-15 treated mice exhibited mild infiltration of inflammatory cells of the lamina propria, no mucosal damages and a minimal increased size of villi (histological score=1.6/6). Levels of TNFα, IL-17 and IL-6 mRNA in the colon were significantly reduced in CRB-15 treated mice (p<0.04 vs IgG2), indicating a decrease in colon inflammation. CRB-15 improved femur BMD (+10.6% vs IgG2a, p<0.002), vertebral trabecular bone volume fraction (BV/TV, +19.7% vs IgG2a, p<0.05) and thickness (+11.6% vs IgG2a, p<0.02). A modest but not significant increase in trabecular BV/TV was observed at the distal femur. Cortical thicknesswas also higher at themidshaft femur in CRB-15 treatedmice (+8.3% vs IgG2a, p<0.02). In conclusion, we confirm and extend our results about the effects of CRB-15 in colitis. Antagonizing IL-15 may exert favorable effects on intestinal inflammation and prevent bone loss and microarchitecture alterations induced by colitis. This article is part of a Special Issue entitled ECTS 2011. Disclosure of interest: B. Brounais-Le Royer Grant / Research Support from Novartis Consumer Health Foundation, S. Ferrari-Lacraz: none declared, D. Velin: none declared, X. Zheng: none declared, S. Ferrari: none declared, D. Pierroz: none declared.
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The trabecular bone score (TBS) is a gray-level textural metric that can be extracted from the two-dimensional lumbar spine dual-energy X-ray absorptiometry (DXA) image. TBS is related to bone microarchitecture and provides skeletal information that is not captured from the standard bone mineral density (BMD) measurement. Based on experimental variograms of the projected DXA image, TBS has the potential to discern differences between DXA scans that show similar BMD measurements. An elevated TBS value correlates with better skeletal microstructure; a low TBS value correlates with weaker skeletal microstructure. Lumbar spine TBS has been evaluated in cross-sectional and longitudinal studies. The following conclusions are based upon publications reviewed in this article: 1) TBS gives lower values in postmenopausal women and in men with previous fragility fractures than their nonfractured counterparts; 2) TBS is complementary to data available by lumbar spine DXA measurements; 3) TBS results are lower in women who have sustained a fragility fracture but in whom DXA does not indicate osteoporosis or even osteopenia; 4) TBS predicts fracture risk as well as lumbar spine BMD measurements in postmenopausal women; 5) efficacious therapies for osteoporosis differ in the extent to which they influence the TBS; 6) TBS is associated with fracture risk in individuals with conditions related to reduced bone mass or bone quality. Based on these data, lumbar spine TBS holds promise as an emerging technology that could well become a valuable clinical tool in the diagnosis of osteoporosis and in fracture risk assessment. © 2014 American Society for Bone and Mineral Research.
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(Résumé de l'ouvrage) Das Deuteronomium nimmt sowohl in der Literaturgeschichte der alttestamentlichen Geschichtsbücher Josua bis Könige eine Schlüsselstellung ein als auch für die Entstehung des Pentateuchs. Wie lassen sich diese beiden Funktionen vereinbaren? Mit der Verhältnisbestimmung haben sich namhafte Wissenschafter der Arbeitsgruppe »Biblical and Ancient Near Eastern Law« im Rahmen der Internationalen Treffen der Society of Biblical Literature in Berlin (2002) und Cambridge (2003) befasst. Der Band präsentiert die neuesten Forschungsergebnisse. Er enthält Vorträge von E. Otto, K. Schmid, H.-C. Schmitt, T. Römer, W.M. Schniedewind, G.N. Knoppers, R. Achenbach, M.M. Zahn und C. Nihan.
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Contexte Le plasmocytome isolé osseux est une tumeur maligne rare des cellules plasmocytaires. Les données issues de la littérature ne permettent pas de se déterminer sur la dose radiothérapeutique optimale. Dans cette perspective nous avons conduit une vaste étude rétrospective dans le but d'évaluer l'évolution, les facteurs pronostiques aunsi que la dose radiothérapeutique optimale chez les patients présentant un plasmocytome isolé. Méthodes Nous avons réunis les données de 206 patients présentant un plasmocytome isolé osseux sans évidence de myélome multiple. Chaque cas a été documenté histopathologiquement. La majorité des patients (n=169) ont été traités par radiothérapie seule, 32 par une combinaison radiothérapie-chimiothérapie, et 5 par chirurgie. La durée de suivi médiane fut de 54 mois (7-245) Résultats A 5 ans, la survie globale est de 70%, la survie sans maladie de 46% et le contrôle local de 88%. La durée médiane de développement vers une myélome multiple est de 21 mois (2-135) avec une probabilité à 5 ans de 51 %. Les analyses multivariées indiquent l'âge (<60 ans) et la taille de la tumeur (<5cm) comme facteur favorables pour survie. L'âge (<60ans) se dégage comme facteur favorable pour la survie sans maladie. La localisation de la tumeur (vertébrale vs autre) indique la probabilité de contrôle local. L'âge plus avancé (>60 ans) est le seul prédicteur de myélome multiple. Aucune relation dose-réponse n'est mise en évidence pour les doses supérieures à 30 Gy, même pour lés tumeurs les plus étendues. Conclusions Les patients les plus jeunes, principalement ceux présentant une localisation vertébrale, présentent la meilleure évolution sous traitement radiothérapeutique modéré. La progression vers le myélome multiple reste le problème thérapeutique principal. Les futures investigations devraient se focaliser sur les chimiothérapies adjuvantes ainsi que sur les nouveaux agents thérapeutiques.