Effects of different levels of dietary biotin on the performance and bone structure of broilers

We evaluated the effects of different levels of biotin on broilers performances and bone growth. Biotin was added at concentrations of 100, 200, 300, 400, 500 μg/Kg to a corn and soybean diet for yellow skin broiler production during the whole production cycle. Biotin at dosages of 200, 300, 400 μg/Kg increased growth rate, and, regardless of dosage, feed conversion rate in the second and third period of growth. Femur and tibiotarsus volume was slightly reduced while the bone mineral content of the same bones showed an increase as a result of biotin supplementation. Any particular dose-response effect was recorded with regard to plasma mineral content and ALP activity

The effect of age, anatomical site and bone structure on osteogenesis in New Zealand White rabbit

Among animal models, rabbits are widely used in medical research, as they fill the gap between smaller models, commonly employed in basic science, and larger ones, which are better suited for preclinical trials. Given their rapid growth, rabbits provide a valuable system for the evaluation of bone implants for tissue regeneration. By means of a histomorphometric analysis, here we quantified the mineral apposition rates (MARs) in osteonic, periosteum and endosteum osteogenic fronts, of skeletal elements within femur, tibia, radius, ulna, frontal and parietal bones in New Zealand White rabbits aged 6, 7 and 8 months. Our hypothesis is that the MAR varies according to the skeletal maturity of the animal, and also within the skeletal elements and the osteogenic fronts considered. In the present study we show that the MAR in both femur and tibia is significantly higher than in ulna and radius. We also demonstrate that the MAR in parietal bones is significantly higher compared to the MAR of both frontal and forelimb bones. Contrary to what was expected, the MARs of all the skeletal elements considered were not decreased following full skeletal maturity. Finally, the MAR of the osteonic-osteogenic front is the lowest in all of the skeletal elements considered. In conclusion, these results provide new important insights for the evaluation of bone implants, casting a light on the role of both age and osteogenic fronts on the bone MAR, and providing valuable information on the physiological bone turnover in New Zealand White rabbits

Integrating demand uncertainty in inventory routing for recyclable waste collection

Osteoblast cell adhesion to the extracellular matrix is established through two main pathways: one is mediated by the binding between integrin and a minimal adhesion sequence (RGD) on the extracellular protein, the other is based on the interactions between transmembrane proteoglycans and heparin-binding sequences found in many matrix proteins. The aim of this study is the evaluation in an in vivo endosseous implant model of the early osteogenic response of the peri-implant bone to a biomimetic titanium surface functionalized with the retro-inverso 2DHVP peptide, an analogue of Vitronectin heparin binding site. The experimental plan is based on a bilateral study design of Control and 2DHVP implants inserted respectively in the right and left femur distal metaphysis of adult male Wistar rats (n=16) weighing about 300 gr and evaluated after 15 days. Fluorochromic bone vital markers, were given at specific time frame, in order to monitor the dynamic of new bone deposition. The effect inducted by the peptidomimetic coating on the surrounding bone were qualitatively and quantitatively evaluated by means of static and dynamic histomorphometric analyses performed within three concentric and subsequent circular Regions of Interest (ROI) of equivalent thickness (220 μm), ROI1 adjacent to the interface, ROI2, the middle, and ROI3 the farthest. The data indicated that these functionalized implants stimulated a higher bone apposition rate (p<0,01) and larger and rapid osteoblast activation in terms of mineralising surface within ROI1 compared to the Control (p<0,01). These higher osteoblast recruitment and activation leads to a greater bone to implant contact reached for DHVP samples (p<0,5). This represents an initial stimulus of the osteogenic activity that might results in a faster and better osteointegration process

Primary osteointegration in the study of biomimetic surfaces

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ORGANISATION OF BONY TISSUE: POLARISED LIGHT MICROSCOPIC EXAMINATION OF RABBIT TIBIAS

ANNALI FACOLTA' MEDICINA VETERINARIA DI PARM