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ABSTRACT: Prebiotics and phytoestrogens have sparked great interest because evidence indicates that the consumption of these dietary constituents leads to lower cholesterol levels and inhibition of postmenopausal bone loss. The aim of this study was to determine the effect of both a prebiotic (Synergy) and a phytoestrogen (genistein) on bone and blood lipid levels in an animal model of postmenopausal women.
A 4-week feeding study was conducted in 5-month-old ovariectomized (OVX) Sprague-Dawley rats to examine the effect of genistein, Synergy (a prebiotic), and genistein and Synergy combined on bone density and strength, calcium metabolism, and lipid biomarkers. There were six treatment groups: sham control, OVX control, OVX rats receiving daily estradiol injections, and OVX rats receiving an AIN-93M diet supplement with 200 ppm genistein, with 5% Synergy or with 200 ppm genistein and 5% Synergy combined.
The rats receiving genistein had significantly lower total serum cholesterol concentrations than OVX rats in the control group (17%), OVX rats receiving daily estradiol injections (14%), and OVX rats fed the 5% Synergy diet (19%). Consumption of Synergy improved calcium absorption efficiency (41%) compared with nonconsumption (OVX control). Sham control rats had a significantly higher femoral bone density, as determined by underwater weighing, than did the rats in all of the OVX groups. Genistein consumption restored total and trabecular bone mineral density at the distal femur similar to the levels of sham rats.
Genistein supplementation imparts modest heart health benefits and improves bone geometry at the distal femur, and prebiotic consumption (Synergy) results in improved calcium utilization strength in ovariectomized rats, but the combination produced no synergistic effects.
Menopause (New York, N.Y.) 06/2011; 18(8):923-31. · 3.08 Impact Factor
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ABSTRACT: Calcium-41 (t(1/2) = 10(5) years) can be used after a single dose to follow calcium metabolism over a subject's lifetime. The aims of this study were to expand a (41)Ca kinetic model and estimate bone resorption in women with stable bone loss, compare the rates with those calculated with classical isotope studies, and to use the model to simulate dynamic changes in urinary (41)Ca:Ca ratios and bone balance for the design and interpretation of (41)Ca studies. Forty-two women >5 years post-menopause were given (41)Ca intravenously. Bone mineral content and bone mineral density of total body were measured by dual-energy X-ray absorptiometry at the beginning of the study. Urine collections were made periodically for up to ~5 years while subjects were free living. Urinary (41)Ca:Ca ratios were measured using accelerator mass spectrometry. The isotope data were analyzed by compartmental modeling. Four compartments were necessary to fit the urinary tracer data and total bone calcium. The final model included pathways for absorption, distribution, urinary excretion, and endogenous excretion and was used to calculate rates of bone turnover. Estimates of bone resorption in a subset of the women (n = 13), studied previously in a 3-week balance and full kinetic study with (45)Ca, agreed with those using (41)Ca methodology. Thus, rates of bone resorption can be estimated from (41)Ca urinary data in stable post-menopausal women. The model was used to simulate dynamic changes in urinary (41)Ca:Ca ratios and bone balance, as a result of interventions that perturb calcium metabolism to aid in study design and interpretation.
Analytical and Bioanalytical Chemistry 02/2011; 399(4):1613-22. · 3.78 Impact Factor
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ABSTRACT: Techniques for assessing bone dynamic are in high demand. Calcium (Ca) kinetic studies are currently being used in our clinical studies of bone turnover in adolescents and elderly. The technique has rarely been compared to the standard method of bone dynamic histomorphometry. We perturbed bone turnover through ovariectomy and sub-optimal dietary Ca in a female rat model to cross-calibrate Ca kinetics against dynamic histomorphometry. Kinetic studies involved oral and intravenous administration of (45)Ca and monitoring the tracer in blood, urine, feces, and bone over a 3-day period as part of a metabolic Ca balance study. Histomorphometric indices of mineral apposition rate, mineralizing surface, and bone formation rate were obtained from proximal metaphysis and mid-diaphysis region of tibial bone. Bone mineralization and resorption rates at the whole skeletal level as evaluated by kinetic studies were significantly correlated with the volume-based bone formation rate (BFR/BV) evaluated by dynamic histomorphometry in metaphyseal trabecular bone (r=0.72 and r=0.61, respectively, p<0.001) and surface-based bone formation rate (BFR/BS) in tibial cortex (r=0.63, p<0.001 and r=0.59, p<0.01, respectively). Significant correlations were also demonstrated between bone resorption and mineralization rates at the whole skeletal level (r=0.91, p<0.001) using (45)Ca kinetic data. Ca kinetic modeling showed an increase (p<0.001) in skeletal resorption and formation rates in response to ovariectomy (27.6 vs. 13.8 mg/d for bone resorption and 42.7 vs. 28 mg/d for bone formation in ovariectomized vs. their Sham-operated control animals, respectively). Ca kinetic data also showed that bone formation decreased by 30% and whole bone balance by 50%, when dietary Ca level was reduced from 0.4% to 0.2% (34.2 vs. 23.8 mg/d and 10.4 vs. 5.1 mg/d, respectively, p<0.001). Our data suggest that Ca kinetic studies can be used reliably to rapidly detect changes in bone turnover at the whole skeletal level in response to interventions.
Bone 02/2010; 46(5):1238-43. · 4.02 Impact Factor
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Leecole L Legette,
Berdine R Martin,
Mohammad Shahnazari, Wang-Hee Lee,
William G Helferich,
Junqi Qian,
David J Waters,
Alireza Arabshahi,
Stephen Barnes,
Jo Welch,
David G Bostwick,
Connie M Weaver
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ABSTRACT: Soy isoflavones and their metabolites, with estrogenic activity, have been considered candidates for reducing postmenopausal bone loss. In this study, we examined the effect of dietary equol, a bioactive metabolite of the soy isoflavone daidzein, on equol tissue distribution, bone parameters, and reproductive tissue activity using an adult ovariectomized (OVX) rat model. An 8-wk feeding study was conducted to compare 4 dietary treatments of equol (0, 50, 100, 200 mg/kg diet) in 6-mo-old OVX female Sprague-Dawley rats. A dose response increase in tissue equol concentrations was observed for serum, liver, kidney, and heart, and a plateau occurred at 100 mg equol/kg diet for intestine. In OVX rats receiving 200 mg equol/kg diet, femoral calcium concentration was greater than those receiving lower doses but was still less than SHAM (P < 0.05), and other bone measures were not improved. Tibia calcium concentrations were lower in OVX rats receiving 100 and 200 mg equol/kg diet compared with the OVX control rats. Trabecular bone mineral density of tibia was also lower in equol-fed OVX rats. At this dietary equol intake, uterine weight was higher (P < 0.05) than in other OVX groups but lower than the SHAM-operated intact rats. The 200 mg/kg diet dose of dietary equol significantly increased proliferative index in the uterine epithelium. Dietary equol had no stimulatory effect on mammary gland epithelium. We conclude that in OVX rats, a dietary equol dose that had modest effect on bone also exerts mild uterotropic effects.
Journal of Nutrition 09/2009; 139(10):1908-13. · 3.92 Impact Factor
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ABSTRACT: Over the past years, video communication has emerged as one of the most popular form of communication. Developing the technology for merging the real and virtual image streams and 3D models for better communication is an active research topic. In this paper, we propose a novel method of real time augmentation of 3D objects in 3D scenes using trifocal tensors. The augmentation is robust to arbitrary camera motion. The proposed technique does not require camera calibration, use of fiducials and prior knowledge of structural model of the scene. Also, using background-foreground segmentation, the occlusion issue in augmented reality is addressed. We show several results of the successful working of our algorithm in real life situations. The technique works on a real time video from a USB camera, creative Webcam III on a P IV 1.6 GHz system without any special hardware support.
Multimedia and Expo, 2003. ICME '03. Proceedings. 2003 International Conference on; 08/2003
