Relative bioavailability of manganese in relation to proteinate and sulfate sources for broiler chickens from one to 20 d of age.

The objective of this study was to evaluate the relative bioavailability (RB) of manganese (Mn) proteinate compared to Mn sulfate for broilers fed a diet based on corn and soybean meal for 20 d. The diets of 1,350 male Cobb broilers were supplemented with 0, 35, 70, 105, or 140 mg of Mn/kg of feed in the form of Mn sulfate or Mn proteinate. Weight gain, feed intake, feed conversion, bone strength, and Mn concentration in the tibia and liver, as well as the concentration of type I collagen in the tibia, were evaluated. No differences were observed for performance variables (P > 0.05) or for type I collage concentration in broiler tibia (P > 0.05), regardless of the source and level of supplementation used. Relative bioavailability was determined using bone strength values and Mn concentration in the tibia and liver, assuming Mn sulfate as the standard source (100%) by the slope-ratio method. The RB of Mn proteinate based on bone strength was 111%, based on liver Mn concentration was 128%, and based on tibia Mn concentration was 105%. Manganese proteinate was more bioavailable than Mn sulfate; it can be an important source of supplementation to improve bone quality in broilers.

Comparison between fractal analysis and radiopacity evaluation as a tool for studying repair of an osseous defect in an animal model using biomaterials.

OBJECTIVES: To evaluate bone repair of an osseous defect in a rat animal model through fractal analysis and radiopacity analysis in radiographic images. METHODS: 120 rats were subjected to extraction of their first molar and divided into four groups (n = 6/group) according to the material used for bone grafting: mineralized bovine bone, demineralized bovine bone (DBB), blood clot (BC - control) or Bio-Oss® (BO). The animals were sacrificed after 1, 7, 14, 21 and 49 days and subjected to radiographic evaluation. For fractal analysis (FA), a square regionof interest of 30 × 30 pixels was used, and radiopacity was measured as the mean gray scale (MGS) value for three points of 5 × 5 pixels in the apical, medial and coronal regions of the defect. Histomorphometric evaluation was realized as the gold standard for bone neo-formation and maturation of the new osseous matrix. RESULTS: Histomorphometric evaluation suggested that DBB showed faster mineralized deposition and resulted in more mature bone at the final time point of evaluation. Mineralized bovine bone and Bio-Oss presented similar results. The mineralized groups did not show significant differences in bone maturation. The radiopacity analysis revealed a significant difference (p < 0.05) between the DBB and blood clot groups at the final time point. FA did not show any significant differences at the final time point. CONCLUSIONS: Mean gray scale seemed to be more effective for the quantification of bone repair than FA in the demineralized group in this animal model. Results for the mineralized groups did not reveal a significant difference, leading to the conclusion that both methods are effective.

Endogenous opioids regulate alveolar bone loss in a periodontal disease model.

AIM: The anti-inflammatory effects of exogenous opioid compounds have been demonstrated in several conditions. Nevertheless, the function of endogenous opioid peptides released by the host during inflammatory processes deserves further characterization. The aim of this study was to verify whether endogenous opioids are involved in the progression of the inflammatory alveolar bone loss induced by ligature in rats. MAIN METHODS: The experimental model of periodontal disease (PD) induced by ligature in rats was used throughout the study. A silk ligature was placed around the 2nd upper molar of male Holtzman rats, for 7 days. Rats received different doses of either the non-selective opioid antagonist naloxone or vehicle, locally into the afflicted gingival tissue, from the 3rd to the 5th day after ligature placement. In the 7th experimental day, rats were euthanized and their maxillae were collected for evaluation of alveolar bone and fiber attachment loss, presence of neutrophils (myeloperoxidase assay), osteoclast amount, and levels of cytokines IL-6, TNF-α, IL-8 and IL-10 in periodontal tissues. KEY FINDINGS: Naloxone increased alveolar bone loss significantly, in a dose-dependent manner, in relation to vehicle-treated rats. In contrast, the opioid antagonist did not affect the loss of fiber attachment. The treatment with naloxone also induced a significant increase in myeloperoxidase levels, osteoclast number and cytokines in periodontal tissues of rats with ligature-induced PD. SIGNIFICANCE: Endogenous opioids protect the host from the progression of inflammatory alveolar bone loss that occurs in chronic periodontitis.